Wipes including microencapsulated delivery vehicles and phase change materials

ABSTRACT

Microencapsulated delivery vehicles comprising an active agent are disclosed. In one embodiment, the microencapsulated delivery vehicles are heat delivery vehicles capable of generating heat upon activation. The microencapsulated heat delivery vehicles may be introduced into wet wipes such that, upon activation, the wet wipe solution is warmed resulting in a warm sensation on a user&#39;s skin. Any number of other active ingredients, such as cooling agents and biocides, can also be incorporated into a microencapsulated delivery vehicle.

BACKGROUND OF THE DISCLOSURE

The present disclosure relates generally to microencapsulated deliveryvehicles including an active agent and processes for producing the same,as well as products incorporating the microencapsulated deliveryvehicles and processes for producing the products. More particularly,the present disclosure is directed to microencapsulated heat deliveryvehicles that can be effectively utilized in a wipe or similar productsuch that, upon use and activation, the contents of themicroencapsulated heat delivery vehicles are released and contacted withmoisture, which causes a warming sensation on the skin upon product use.The microencapsulated heat delivery vehicles may include one or moremoisture protective and fugitive layers to improve overall capsuleperformance. Additionally, the microencapsulated delivery vehicles mayinclude other active ingredients.

Wet wipes and dry wipes and related products have been used for sometime by consumers for various cleaning and wiping tasks. For example,many parents have utilized wet wipes to clean the skin of infants andtoddlers before and after urination and/or defecation. Many types of wetwipes are currently commercially available for this purpose.

Today, many consumers are demanding that personal health care products,such as wet wipes, have the ability to not only provide their intendedcleaning function, but also to deliver a comfort benefit to the user. Inrecent studies, it has been shown that baby wet wipes currently on themarket are sometimes perceived to be uncomfortably cold upon applicationto the skin, particularly for newborns. To mitigate this problem, therehave been many attempts to produce warming products to warm the wipes tocomfort the wet wipe users from the inherent “chill” given off by thecontact of the moistened wipes upon the skin.

These warming products are generally electrically operated and come intwo distinct styles. One is an “electric blanket” style which is sizedto wrap around the external surfaces of a plastic wet wipes container.The other is a self-contained plastic “appliance” style which warms thewet wipes with its internally positioned heating element. Though suchcurrently known and available wet wipe warming products typicallyachieve their primary objective of warming the wet wipe prior to use,they possess certain deficiencies, which can detract from their overallutility and desirability.

Perhaps the biggest deficiency of the current wet wipe warming productsis their inability to sustain the moisture content of the wet wipes.More specifically, drying of the wet wipes occurs due to heating oftheir moisture which accelerates dehydration. As a result, wet wipes maybecome dried-out and unusable.

Other complaints by wipe warmer users include discoloration of the wetwipes after heating, which appears to be inevitable because of areaction of various chemicals in the wipes upon the application of heat.Wipe warmer users further complain about warmer inconvenience andpotential electrical fire hazards, which can result with the use ofelectrical warming products.

Based on the foregoing, there is a need in the art for wet wipes thatcan produce a warming sensation just prior to, or at the point of use,without using external heating products. It would be desirable if thewet wipes could produce a warming sensation within less than about 10seconds after activation and raise the temperature of the wet wipesolution and the wet wipe base substrate at least 20° C. or more for atleast 20 seconds.

SUMMARY OF THE DISCLOSURE

The present disclosure relates to microencapsulated delivery vehicles,such as microencapsulated heat delivery vehicles or microencapsulateddelivery vehicles including a cooling agent, suitable for use inpersonal care products, such as wet wipes, dry wipes, lotions, creams,cloths, and the like. Other active agents may also be employed in themicroencapsulated delivery vehicles.

In one embodiment, the microencapsulated heat delivery vehicles, uponactivation in a wet wipe, for example, can produce a warming sensationon the skin when the wet wipe is used. The microencapsulated heatdelivery vehicles include a core composition comprising a matrixmaterial, such as mineral oil, and a heating agent, such as magnesiumchloride. Optionally, the core composition may also include a surfactantand a hydrophobic wax material surrounding the heating agent to improveoverall performance. In some cases, the core composition of themicroencapsulated heat delivery vehicle may contain a small amount ofun-used encapsulating activator as described herein. The corecomposition and components therein are encapsulated in a thin capsulethat may have one or more moisture protective layers and/or fugitivelayers thereon to impart additional advantageous characteristics. Uponuse in a wet wipe, the capsules containing the core compositionincluding the matrix material and heating agent (and any other optionalcomponents) are ruptured such that the heating agent contacts waterpresent in the wet wipe solution and releases heat to cause a warmingsensation on the skin.

The present disclosure also relates to processes for manufacturing amicroencapsulated delivery vehicle suitable for use in personal careproducts, such as wet wipes. In one embodiment, a composition includinga core composition comprising a matrix material, such as mineral oil,and a heating agent that may or may not be surrounded by a hydrophobicwax material, an encapsulating activator, and optionally, a surfactant,is introduced into a liquid solution containing a crosslinkablecompound. Once in the liquid solution, the encapsulating activatorreacts with the crosslinkable compound to form an encapsulation layerthat surrounds the core composition. After a sufficient time has passed,the encapsulated core composition containing the heating agent isremoved from the liquid solution. Optionally, the encapsulated corecomposition may then be subjected to one or more further processingsteps to introduce additional layers of encapsulation onto the formedshell. These layers may include, for example, a moisture protectivelayer to reduce the potential for premature heat release throughdeactivation of the heating agent through contact with water, and afugitive layer to impart mechanical strength to the capsule.

The present disclosure further relates to self-warming wipes and methodsof manufacturing the self-warming wipes. In one embodiment, the wipesare self-warming wet wipes. Generally, the wet wipes comprise a fibroussheet material, a wetting solution, and a microencapsulated heatdelivery vehicle that includes an encapsulation layer that surrounds acore composition including a heating agent. When the microencapsulatedheat delivery vehicle is ruptured, the contents of the microencapsulatedheat delivery vehicle contact the wetting solution and generate heat tocreate a warming sensation at the surface of the wet wipe.

The present disclosure further relates to self-warming wet wipescomprising a fibrous sheet material, a wetting solution, a heat deliveryvehicle, and a first phase change material. The first phase changematerial present in the wet wipe is capable of providing thermalstability to the wipe and keeping the wet wipe from becoming too hotupon use.

The present disclosure further relates to cleansing compositions for usein cleaning both animate and inanimate surfaces. The cleansingcompositions generally include the microencapsulated heat deliveryvehicle in combination with a biocide agent. The cleansing compositionsmay further be incorporated in cleansing products. For example, in oneembodiment, the cleansing composition is used in combination with a wetwipe. When the microencapsulated heat delivery vehicle contained in thewet wipe solution is ruptured, the contents of the microencapsulatedheat delivery vehicle contact the wetting solution and generate heat,which can activate or enhance the biocidal function of the biocideagent.

As such, the present disclosure is directed to a microencapsulated heatdelivery vehicle comprising a core composition surrounded by anencapsulation layer. The core composition material comprises a matrixmaterial and a heating agent. The microencapsulated heat deliveryvehicle has a diameter of from about 5 micrometers to about 5000micrometers.

The present disclosure is further directed to a substantiallyfluid-impervious microencapsulated heat delivery vehicle comprising acore composition, an encapsulation layer surrounding the corecomposition, and a moisture protective layer surrounding theencapsulation layer. The core composition comprises a matrix materialand a heating agent and the microencapsulated heat delivery vehicle hasa diameter of from about 5 micrometers to about 5000 micrometers.

The present disclosure is further directed to a stabilized substantiallyfluid-impervious microencapsulated heat delivery vehicle comprising acore composition, an encapsulation layer surrounding the corecomposition, a moisture protective layer surrounding the encapsulationlayer, and a fugitive layer surrounding the moisture protective layer.The core composition comprises a matrix material and a heating agent andthe microencapsulated heat delivery vehicle has a diameter of from about5 micrometers to about 5000 micrometers.

The present disclosure is further directed to a microencapsulated heatdelivery vehicle comprising a core composition surrounded by anencapsulation layer. The core composition comprises a matrix materialand a heating agent, and the heating agent is surrounded by ahydrophobic wax material. The microencapsulated heat delivery vehiclehas a diameter of from about 5 micrometers to about 5000 micrometers.

The present disclosure is further directed to a substantiallyfluid-impervious microencapsulated heat delivery vehicle comprising acore composition, an encapsulation layer surrounding the corecomposition, and a moisture protective layer surrounding theencapsulation layer. The core composition comprises a matrix materialand a heating agent, and the heating agent is surrounded by ahydrophobic wax material. The microencapsulated heat delivery vehiclehas a diameter of from about 5 micrometers to about 5000 micrometers.

The present disclosure is further directed to a stabilized substantiallyfluid-impervious microencapsulated heat delivery vehicle comprising acore composition, an encapsulation layer surrounding the corecomposition, a moisture protective layer surrounding the encapsulationlayer, and a fugitive layer surrounding the moisture protective layer.The core composition comprises a matrix material and a heating agent.The heating agent is surrounded by a hydrophobic wax material. Themicroencapsulated heat delivery vehicle has a diameter of from about 5micrometers to about 5000 micrometers.

The present disclosure is further directed to a stabilized substantiallyfluid-impervious microencapsulated heat delivery vehicle comprising corecomposition, an encapsulation layer surrounding the core composition, amoisture protective layer surrounding the encapsulation layer, and afugitive layer surrounding the moisture protective layer. The corecomposition comprises mineral oil, magnesium chloride, and a surfactant,wherein the magnesium chloride is surrounded by a hydrophobic waxmaterial. The encapsulation layer comprises crosslinked sodium alginateand the moisture protection layer comprises vinyl toluene acrylate. Thefugitive layer comprises starch. The encapsulation layer has a thicknessof from about 1 micrometer to about 20 micrometers and themicroencapsulated heat delivery vehicle has a diameter of from about 5micrometers to about 5000 micrometers.

The present disclosure is further directed to a method of making amicroencapsulated heat delivery vehicle. The method comprises firstmixing a matrix material, a heating agent and an encapsulating activatorto form a core composition. The core composition is then introduced intoa liquid solution comprising a crosslinkable compound to form themicroencapsulated heat delivery vehicle. Finally, the microencapsulatedheat delivery vehicle is removed from the liquid solution.

The present disclosure is further directed to a method of making amicroencapsulated heat delivery vehicle. The method comprises firstmixing a matrix material and a heating agent to form a core composition.The core composition is then introduced into a liquid solutioncomprising a crosslinkable compound to form the microencapsulated heatdelivery vehicle. Finally, the microencapsulated heat delivery vehicleis removed from the liquid solution.

The present disclosure is further directed to a method of making asubstantially fluid-impervious microencapsulated heat delivery vehicle.The method comprises first mixing a matrix material, a heating agent,and an encapsulating activator to form a core composition. The corecomposition is then introduced into a liquid solution comprising acrosslinkable compound to form a microencapsulated heat deliveryvehicle. The microencapsulated heat delivery vehicle is then removedfrom the liquid solution and a moisture protective layer is applied tothe microencapsulated heat delivery vehicle such that the moistureprotective layer surrounds the microencapsulated heat delivery vehicle.

The present disclosure is further directed to a method of making astabilized substantially fluid-impervious microencapsulated heatdelivery vehicle. The method comprises first mixing a heating agent, amatrix material, and an encapsulating activator to form a corecomposition. The core composition is then introduced into a liquidsolution comprising a crosslinkable compound to form a microencapsulatedheat delivery vehicle. The microencapsulated heat delivery vehicle isthen removed from the liquid solution and a moisture protective layer isapplied to the microencapsulated heat delivery vehicle such that themoisture protective layer surrounds the microencapsulated heat deliveryvehicle. Finally, a fugitive layer is applied to the microencapsulatedheat delivery vehicle such that the fugitive layer surrounds themoisture protective layer.

The present disclosure is further directed to a wet wipe comprising afibrous sheet material, a wetting solution, and a microencapsulated heatdelivery vehicle. The microencapsulated heat delivery vehicle includesan encapsulation layer that surrounds a core composition including amatrix material and a heating agent.

The present disclosure is further directed to a dry wipe comprising afibrous sheet material and a microencapsulated heat delivery vehicle.The microencapsulated heat delivery vehicle includes an encapsulationlayer that surrounds a core composition comprising a matrix material anda heating agent.

The present disclosure is further directed to a method of manufacturinga self-warming wet wipe. The method comprises embedding amicroencapsulated heat delivery vehicle inside of a fibrous sheetmaterial.

The present disclosure is further directed to a method of manufacturinga self-warming wet wipe. The method comprises depositing amicroencapsulated heat delivery vehicle on an outer surface of a fibroussheet material.

The present disclosure is further directed to a wet wipe comprising afibrous sheet material, a wetting solution, a microencapsulated heatdelivery vehicle, and a first phase change material, wherein the firstphase change material is capable of providing thermal stability to thewipe.

The present disclosure is further directed to a dry wipe comprising afibrous sheet material, a microencapsulated heat delivery vehicle, and afirst phase change material, wherein the first phase change material iscapable of providing thermal stability to the wipe.

The present disclosure is further directed to a method of manufacturinga self-warming wet wipe. The method comprises first embedding amicroencapsulated heat delivery vehicle inside of a fibrous sheetmaterial and then embedding a first phase change material inside of thefibrous sheet material. Finally, the fibrous sheet material containingthe microencapsulated heat delivery vehicle and the first phase changematerial is contacted with a wetting solution.

The present disclosure is further directed to a method of manufacturinga self-warming wet wipe. The method comprises first depositing amicroencapsulated heat delivery vehicle on an outer surface of a fibroussheet material and depositing a first phase change material on the outersurface of the fibrous sheet material. Finally, the fibrous sheetmaterial containing the microencapsulated heat delivery vehicle andfirst phase change material are contacted with a wetting solution.

The present disclosure is further directed to a cleansing compositioncomprising a biocide agent and a microencapsulated heat deliveryvehicle. The microencapsulated heat delivery vehicle comprises anencapsulation layer surrounding a core composition comprising a matrixmaterial and a heating agent.

The present disclosure is further directed to a wet wipe comprising afibrous sheet material, a wetting solution, a biocide agent, and amicroencapsulated heat delivery vehicle. The microencapsulated heatdelivery vehicle comprises an encapsulation layer surrounding a corecomposition comprising a matrix material and a heating agent.

The present disclosure is further directed to a method of manufacturinga biocidal wet wipe. The method comprises embedding a microencapsulatedheat delivery vehicle inside of the fibrous sheet material, embedding abiocide agent inside of the fibrous sheet material, and contacting thefibrous sheet material containing the microencapsulated heat deliveryvehicle and biocide agent with a wetting solution.

The present disclosure is further directed to a method of manufacturinga biocidal wet wipe. The method comprises depositing a microencapsulatedheat delivery vehicle on an outer surface of a fibrous sheet material,depositing a biocide agent on an outer surface of the fibrous sheetmaterial, and contacting the fibrous sheet material containing themicroencapsulated heat delivery vehicle and biocide agent with a wettingsolution.

The present disclosure is further directed to a microencapsulateddelivery vehicle comprising a core composition surrounded by anencapsulation layer. The core composition comprises a matrix materialand a cooling agent and the microencapsulated delivery vehicle has adiameter of from about 5 micrometers to about 5000 micrometers.

The present disclosure is further directed to a substantiallyfluid-impervious microencapsulated delivery vehicle comprising a corecomposition, an encapsulation layer surrounding the core composition,and a moisture protective layer surrounding the encapsulation layer. Thecore. composition comprises a matrix material and a cooling agent andthe microencapsulated heat delivery vehicle has a diameter of from about5 micrometers to about 5000 micrometers.

The present disclosure is further directed to a stabilized substantiallyfluid-impervious microencapsulated delivery vehicle comprising a corecomposition, an encapsulation layer surrounding the core composition, amoisture protective layer surrounding the encapsulation layer, and afugitive layer surrounding the moisture protective layer. The corecomposition comprises a matrix material and a cooling agent and themicroencapsulated delivery vehicle has a diameter of from about 5micrometers to about 5000 micrometers.

The present disclosure is further directed to a microencapsulateddelivery vehicle comprising a core composition surrounded by anencapsulation layer. The core composition comprises a matrix materialand a cooling agent. The cooling agent is surrounded by a hydrophobicwax material. The microencapsulated heat delivery vehicle has a diameterof from about 5 micrometers to about 5000 micrometers.

Other features of the present disclosure will be in part apparent and inpart pointed out hereinafter.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts a cross sectional view of a microencapsulated heatdelivery vehicle of the present disclosure.

FIG. 2 depicts a fluidized bed coating apparatus for use imparting amoisture protective layer to a microencapsulated heat delivery vehicle.

FIG. 3 is a graph illustrating the heat generation rate for five sizeranges of calcium chloride that were tested in accordance with anexperiment described herein.

FIG. 4 is a graph illustrating the heat generation rate for four sizeranges of magnesium chloride that were tested in accordance with anexperiment described herein.

FIG. 5 is a graph illustrating the conductivity of a solution includinga microencapsulated delivery vehicle having a moisture protective layermade in accordance with an experiment described herein.

FIG. 6 is a graph illustrating the ability of various samples ofmicroencapsulated heat delivery vehicles including moisture protectivelayers to generate heat as tested in accordance with an experimentdescribed herein.

FIG. 7 is a graph illustrating the ability of microencapsulated heatdelivery vehicles including various coating levels of moistureprotective layers to generate heat as tested in accordance with anexperiment described herein.

FIG. 8 is a graph illustrating the ability of microencapsulated heatdelivery vehicles including moisture protective layers to generate heatafter being flooded over various intervals of time with a wettingsolution as tested in accordance with an experiment described herein.

FIGS. 9-11 are graphs illustrating the rupture force required to rupturevarious microencapsulated heat delivery vehicles as tested in accordancewith an experiment described herein.

FIGS. 12-14 are graphs illustrating the rupture force required torupture various microencapsulated heat delivery vehicles as tested inaccordance with an experiment described herein.

FIGS. 15-17 are graphs illustrating the rupture force required torupture various microencapsulated heat delivery vehicles as tested inaccordance with an experiment described herein.

FIGS. 18-24 are graphs illustrating the rupture force required torupture various microencapsulated heat delivery vehicles as tested inaccordance with an experiment described herein.

DEFINITIONS

Within the context of this specification, each term or phrase below willinclude, but not be limited to, the following meaning or meanings:

-   -   (a) “Bonded” refers to the joining, adhering, connecting,        attaching, or the like, of two elements. Two elements will be        considered to be bonded together when they are bonded directly        to one another or indirectly to one another, such as when each        is directly bonded to intermediate elements.    -   (b) “Film” refers to a thermoplastic film made using a film        extrusion and/or forming process, such as a cast film or blown        film extrusion process. The term includes apertured films, slit        films, and other porous films which constitute liquid transfer        films, as well as films which do not transfer liquid.    -   (c) “Layer” when used in the singular can have the dual meaning        of a single element or a plurality of elements.    -   (d) “Meltblown” refers to fibers formed by extruding a molten        thermoplastic material through a plurality of fine, usually        circular, die capillaries as molten threads or filaments into        converging high velocity heated gas (e.g., air) streams which        attenuate the filaments of molten thermoplastic material to        reduce their diameter, which may be to microfiber diameter.        Thereafter, the meltblown fibers are carried by the high        velocity gas stream and are deposited on a collecting surface to        form a web of randomly dispersed meltblown fibers. Such a        process is disclosed for example, in U.S. Pat. No. 3,849,241 to        Butin et al. (Nov. 19, 1974). Meltblown fibers are microfibers        which may be continuous or discontinuous, are generally smaller        than about 0.6 denier, and are generally self bonding when        deposited onto a collecting surface. Meltblown fibers used in        the present disclosure are preferably substantially continuous        in length.    -   (e) “Nonwoven” refers to materials and webs of material which        are formed without the aid of a textile weaving or knitting        process.    -   (f) “Polymeric” includes, but is not limited to, homopolymers,        copolymers, such as for example, block, graft, random and        alternating copolymers, terpolymers, etc. and blends and        modifications thereof. Furthermore, unless otherwise        specifically limited, the term “polymeric” shall include all        possible geometrical configurations of the material. These        configurations include, but are not limited to, isotactic,        syndiotactic and atactic symmetries.    -   (g) “Thermoplastic” describes a material that softens when        exposed to heat and which substantially returns to a nonsoftened        condition when cooled to room temperature.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present disclosure relates to microencapsulated delivery vehicles,such as microencapsulated heat delivery vehicles, suitable for use inpersonal care products such as wet wipes and dry wipes. The presentdisclosure also relates to self warming wipes that include amicroencapsulated heat delivery vehicle and, optionally, a phase changematerial. The microencapsulated heat delivery vehicles, upon activation,are capable of evolving heat and causing a warming sensation on the skinof a user of the wet wipe. The microencapsulated heat delivery vehiclesas described herein may include one or more encapsulating layers,moisture protective layers, and fugitive layers to impart variouscharacteristics upon the encapsulated vehicles and the products in whichthey are used. Surprisingly, it has been discovered that anencapsulating activator can be included directly within a corecomposition and the combination introduced into a solution containing acrosslinkable compound and the thickness of the resulting crosslinkedencapsulation layer closely controlled. Furthermore, in some embodimentsdisclosed herein, the encapsulating activator can also act as theheating agent. Additional active ingredients may also be included, withor without the heating agent, in the microencapsulated deliveryvehicles.

Although discussed primarily herein in relation to microencapsulatedheat delivery vehicles, it will be recognized by one skilled in the artbased on the disclosure herein that other active agents or activeingredients, in addition to, or in place of, the heating agent, may beincorporated into the microencapsulated delivery vehicles describedherein. For example, the microencapsulated delivery vehicles may includea heating agent and a biocide agent, or may simply include a biocideagent. A number of suitable active agents for incorporation into themicroencapsulated delivery vehicles described herein are set forthbelow.

As noted above, the microencapsulated heat delivery vehicles asdescribed herein may include a number of components and layers. Turningnow to FIG. 1, there is shown a cross sectional view of amicroencapsulated heat delivery vehicle 2 of the present disclosure. Themicroencapsulated heat delivery vehicle 2 includes a fugitive layer 4surrounding a moisture protective layer 6 that surrounds anencapsulation layer 8. Additionally, microencapsulated heat deliveryvehicle 2 includes a core composition 10 that includes a matrix material100 and a heating agent 12 surrounded by a hydrophobic wax material 14,and an encapsulating activator 16. Each of these layers and components,some of which are optional, are more thoroughly discussed below.

The microencapsulated heat delivery vehicles as described herein aredesirably of a size such that, when incorporated into a personal careproduct such as a wet wipe, they cannot readily be felt on the skin bythe user. Generally, the microencapsulated heat delivery vehicles have adiameter of from about 5 micrometers to about 10,000 micrometers,desirably from about 5 micrometers to about 5000 micrometers, desirablyfrom about 50 micrometers to about 1000 micrometers, and still moredesirably from about 300 micrometers to about 700 micrometers.

The core composition includes all of the components or materials thatare encapsulated as described herein by, for example, a crosslinkedpolymeric system, to form the microencapsulated delivery vehicles. Thecore composition may include, for example, the matrix material (i.e.,mineral oil), the heating agent (i.e., magnesium chloride) (or otheractive agent as described herein), a surfactant, an encapsulatingactivator, and a hydrophobic wax material that surrounds the heating (orother active) agent.

Generally, the core composition is present in the microencapsulated heatdelivery vehicle in an amount of from about 0.1% (by weightmicroencapsulated heat delivery vehicle) to about 99.99% (by weightmicroencapsulated heat delivery vehicle), desirably from about 1% (byweight microencapsulated heat delivery vehicle) to about 95% (by weightmicroencapsulated heat delivery vehicle), more desirably from about 5%(by weight microencapsulated heat delivery vehicle) to about 90% (byweight microencapsulated heat delivery vehicle), more desirably fromabout 10% (by weight microencapsulated heat delivery vehicle) to about80% (by weight microencapsulated heat delivery vehicle), more desirablyfrom about 15% (by weight microencapsulated heat delivery vehicle) toabout 70% (by weight microencapsulated heat delivery vehicle), and evenmore desirably from about 20% (by weight microencapsulated heat deliveryvehicle) to about 40% (by weight microencapsulated heat deliveryvehicle).

The matrix material included in the core composition is used as acarrying or bulking agent for other components of the microencapsulatedheat delivery vehicle, including, for example, the heating agent, thesurfactant, and the encapsulating activator. Although generallypreferred to be a liquid material, the matrix material may also be a lowmelting material that is a solid at room temperature. The matrixmaterial is desirably a material that is emulsifiable in water.Preferred liquid matrix materials include oils commonly used incommercial cosmetic applications that may impart some skin benefit tothe user, such as a moisturizing or lubricating benefit. Generally,these oils are hydrophobic oils.

Specific examples of suitable liquid matrix materials include, forexample, mineral oil, isopropyl myristate, silicones, copolymers such asblock copolymers, waxes, butters, exotic oils, dimethicone, thermoionicgels, plant oils, animal oils, and combinations thereof. One preferredmaterial for use as the matrix material is mineral oil. The matrixmaterial is generally present in the core composition of themicroencapsulated heat delivery vehicle in an amount of from about 1%(by weight core composition) to about 99% (by weight core composition),desirably from about 10% (by weight core composition) to about 95% (byweight core composition), more desirably from about 15% (by weight corecomposition) to about 75% (by weight core composition), more desirablyfrom about 20% (by weight core composition) to about 50% (by weight corecomposition), more desirably from about 25% (by weight core composition)to about 45% (by weight core composition), and even more desirably fromabout 30% (by weight core composition) to about 40% (by weight corecomposition).

The microencapsulated heat delivery vehicle as disclosed herein alsoincludes a heating agent that is contained in the core composition. Theheating agent releases heat when contacted with water and may result ina warm feeling on the skin if used in combination with a personal careproduct such as a wet wipe. Suitable heating agents for use in themicroencapsulated heat delivery vehicles include compounds with anexothermic heat of hydration and compounds with an exothermic heat ofsolution. Suitable compounds for use as heating agents in the corecomposition include, for example, calcium chloride, magnesium chloride,zeolites, aluminum chloride, calcium sulfate, magnesium sulfate, sodiumcarbonate, sodium sulfate, sodium acetate, metals, slaked lime, quicklime, glycols, and combinations thereof. The heating agents may be ineither hydrous or anhydrous forms, although anhydrous forms aregenerally preferred. Particularly preferred compounds include magnesiumchloride and calcium chloride.

The heating agent is generally included in the core composition of themicroencapsulated heat delivery vehicle in an amount of from about 0.1%(by weight core composition) to about 98% (by weight core composition),desirably from about 1% (by weight core composition) to about 80% (byweight core composition), more desirably from about 20% (by weight corecomposition) to about 70% (by weight core composition), more desirablyfrom about 30% (by weight core composition) to about 60% (by weight corecomposition), more desirably from about 35% (by weight core composition)to about 55% (by weight core composition), and even more desirably about55% (by weight core composition).

The heating agent utilized in the microencapsulated heat deliveryvehicle generally has a particle size of from about 0.05 micrometers toabout 4000 micrometers, desirably from about 10 micrometers to about1000 micrometers, desirably from about 10 micrometers to about 500micrometers, and more desirably from about 10 micrometers to about 100micrometers to facilitate substantial and continuous heat release. Inone specific embodiment, a particle size of from about 149 micrometersto about 355 micrometers is preferred. Although many heating agents asdescribed herein are commercially available in a number of particlesizes, it will be recognized by one skilled in the art that any numberof techniques can be used to grind and produce the desired particlesizes.

Along with the heating agent, a surfactant may optionally be included inthe core composition. As used herein, “surfactant” is intended toinclude surfactants, dispersants, gelling agents, polymeric stabilizers,structurants, structured liquids, liquid crystals, Theologicalmodifiers, grinding aids, defoamers, block copolymers, and combinationsthereof. If a surfactant is utilized, it should be substantiallynon-reactive with the heating agent. A surfactant may be added alongwith a heating agent and matrix material to the core composition as agrinding and mixing aid for the heating agent and to reduce the surfacetension of the core composition and allow for better mixing with waterand an increase in heating ability upon use. In one embodiment, the useof a surfactant in the core composition generally allows for higherloading of the heating material (or other active agent as describedherein) within the core composition without unwanted flocculation of theheating material occurring, which can hinder heat release by the heatingagent.

Any one of a number of surfactant types including anionic, cationic,nonionic, zwitterionic, and combinations thereof can be utilized in thecore composition. One skilled in the art will recognize, based on thedisclosure herein, that different heating agents in combination withdifferent matrix materials may benefit from one type of surfactant morethan another; that is, the preferred surfactant for one chemistry may bedifferent than the preferred surfactant for another. Particularlydesirable surfactants will allow the core composition including thematrix material, heating agent, and surfactant mixture to have asuitable viscosity for thorough mixing; that is, the surfactant will notresult in the mixture having an undesirably high viscosity. Generally,low HLB surfactants are desirable; that is, surfactants having an HLB ofless than about 7. Examples of commercially available surfactantssuitable for use in the matrix material include, for example, Antiterra207 (BYK Chemie, Wallingford, Conn.) and BYK-P104 (BYK Chemie).

When included in the core composition of the microencapsulated heatdelivery vehicles of the present disclosure, the surfactant is generallypresent in an amount of from about 0.01% (by weight core composition) toabout 50% (by weight core composition), desirably from about 0.1% (byweight core composition) to about 25% (by weight core composition), moredesirably from about 0.1% (by weight core composition) to about 10% (byweight core composition), more desirably from about 1% (by weight corecomposition) to about 5% (by weight core composition), and still moredesirably about 1% (by weight core composition).

As will be described in more detail below, during the manufacturingprocess for the microencapsulated heat delivery vehicle, the corecomposition including the matrix material and the heating agent isintroduced into an aqueous environment. During contact with this aqueousenvironment, it may be possible for the heating agent present in thecore composition to come into contact with water. This contact canresult in a loss of potency and deactivation of the heating agent andrender the resulting microencapsulated heat delivery vehicle ineffectivefor its intended purpose. As such, in one embodiment of the presentdisclosure, the heating agent included in the core composition issubstantially completely surrounded by a hydrophobic wax material priorto being introduced into the core composition and ultimately into theaqueous environment. As used herein, the term “hydrophobic wax material”means a material suitable to coat and protect the heating agent (orother active agent) from water. This hydrophobic wax material mayprovide the heating agent with temporary water protection during thetimeframe of exposure to the aqueous environment; that is, thehydrophobic wax material may keep water from contacting the heatingagent. Although the hydrophobic wax material provides protection of theheating agent during treatment of the core composition in an aqueousenvironment, in one embodiment it will gradually dissolve away and offof the heating agent within the core composition over time; that is, thehydrophobic wax material dissolves into the bulk of the core compositionover time and off of the heating agent so that the heating agent can bedirectly contacted with water upon activation in a wipe or otherproduct.

In an alternative embodiment, the hydrophobic wax material does notsubstantially dissolve into the core composition and off of the heatingagent but is removed from the heating agent at the time of use throughshearing or disruption of the hydrophobic wax material; that is, thehydrophobic wax material is mechanically broken off of the heating agentto allow the heating agent access to water.

It is generally desirable to have substantially complete coverage of theheating agent with the hydrophobic wax material to ensure that theheating agent is not susceptible to contact with water during theintroduction of the core composition into the aqueous liquid asdescribed herein. When contacted with a substantially continuous layerof hydrophobic wax material, the core composition including the matrixmaterial and the heating agent can be encapsulated in the liquidenvironment without the heating agent losing potency. Generally, thehydrophobic wax material may be applied to the heating agent in fromabout 1 to about 30 layers, desirably in from about 1 to about 10layers.

Generally, the hydrophobic wax material is present on the heating agentin an amount of from about 1% (by weight heating agent) to about 50% (byweight heating agent), desirably from about 1% (by weight heating agent)to about 40% (by weight heating agent), more desirably from about 1% (byweight heating agent) to about 30% (by weight heating agent), and evenmore desirably from about 1% (by weight heating agent) to about 20% (byweight heating agent). At these levels, there is sufficient hydrophobicwax material present on the heating agent to provide the desired levelof protection, yet not too much to keep it from dissolving over timeinto the core composition to allow for water to access the heating agentat the desired time.

Suitable hydrophobic wax materials for coating the heating agent arerelatively low temperature melting wax materials. Although otherhydrophobic low temperature melting materials can be used to coat theheating agent in accordance with the present disclosure, low temperaturemelting hydrophobic wax materials are generally preferred. In oneembodiment, the hydrophobic wax material has a melting temperature ofless than about 140° C., desirably less than about 90° C. to facilitatethe coating of the heating agent as described below.

Suitable hydrophobic wax materials for use in coating the heating agent(or other active agent) include, for example, organic ester and waxycompounds derived from animal, vegetable, and mineral sources includingmodifications of such compounds in addition to synthetically producedmaterials having similar properties. Specific examples that may be usedalone or in combination include glyceryl tristearate, glyceryldistearate, canola wax, hydrogenated cottonseed oil, hydrogenatedsoybean oil, castor wax, rapeseed wax, beeswax, carnauba wax, candelillawax, microwax, polyethylene, polypropylene, epoxies, long chainalcohols, long chain esters, long chain fatty acids such as stearic acidand behenic acid, hydrogenated plant and animal oils such as fish oil,tallow oil, and soy oil, microcrystalline waxes, metal stearates andmetal fatty acids. Specific commercially available hydrophobic waxmaterials include, for example, Dynasan™ 110, 114, 116, and 118(commercially available from DynaScan Technology Inc., Irvine, Calif.),Sterotex™ (commercially available from ABITEC Corp., Janesville, Wis.);Dritex C (commercially available from Dritex International, LTD., Essex,U.K.); Special Fat™ 42, 44, and 168T.

As noted herein, the microencapsulated heat delivery vehicles include anencapsulation layer that substantially completely surrounds the corecomposition that includes the matrix material, heating agent andoptionally the hydrophobic wax material and the surfactant (andoptionally an encapsulating activator as discussed below). Theencapsulation layer allows the core composition including the heatingagent or other active agent to undergo further processing and usewithout a loss of structural integrity; that is, the encapsulation layerprovides structural integrity to the core composition and its contentsto allow for further processing.

Although described in more detail below, and generally in relation to acrosslinked polymeric material, the encapsulation layer may be comprisedof a polymeric material, a crosslinked polymeric material, a metal, aceramic or a combination thereof, that results in a shell material thatmay be formed during manufacturing. Specifically, the encapsulationlayer may be comprised of crosslinked sodium alginate, anionic dispersedlatex emulsions, crosslinked polyacrylic acid, crosslinked polyvinylalcohol, crosslinked polyvinyl acetate, silicates, carbonates, sulfates,phosphates, borates, polyvinyl pyrolidone, PLA/PGA, thermoionic gels,urea formaldehyde, melamine formaldehyde, polymelamine, crosslinkedstarch, nylon, ureas, hydrocolloids, and combinations thereof. Oneparticularly preferred crosslinked polymeric system is crosslinkedsodium alginate.

The encapsulation layer present in the microencapsulated heat deliveryvehicle generally has a thickness of from about 0.1 micrometers to about500 micrometers, desirably from about 1 micrometer to about 100micrometers, more desirably from about 1 micrometer to about 50micrometers, more desirably from about 1 micrometer to about 20micrometers, and even more desirably from about 10 micrometers to about20 micrometers. At these thicknesses, the crosslinked polymeric layerhas a sufficient thickness to provide its intended function. Theencapsulation layer may be one discrete layer, or may be comprised ofmultiple layers added in one or more steps. Suitable methods formeasuring the thickness of the encapsulation layer (once fractured), andthe other optional layers described herein, include Scanning ElectronMicroscopy (SEM) and Optical Microscopy.

Generally, the encapsulation layer will be present in from about 1 layerto about 30 layers, desirably in from about 1 layer to about 20 layers,and more desirably in from about 1 layer to about 10 layers to providefurther protection.

The encapsulation layer is generally present in the microencapsulatedheat delivery vehicle in an amount of from about 0.001% (by weightmicroencapsulated heat delivery vehicle) to about 99.8% (by weightmicroencapsulated heat delivery vehicle), desirably from about 0.1% (byweight microencapsulated heat delivery vehicle) to about 90% (by weightmicroencapsulated heat delivery vehicle), more desirably from about 1%(by weight microencapsulated heat delivery vehicle) to about 75% (byweight microencapsulated heat delivery vehicle), more desirably fromabout 1% (by weight microencapsulated heat delivery vehicle) to about50%(by weight microencapsulated heat delivery vehicle), more desirablyfrom about 1% (by weight microencapsulated heat delivery vehicle) toabout 20% (by weight microencapsulated heat delivery vehicle), and stillmore desirably about 1% (by weight microencapsulated heat deliveryvehicle).

The microencapsulated heat delivery vehicle as described herein mayoptionally comprise a moisture protective layer to produce asubstantially fluid-impervious microencapsulated heat delivery vehicle.As used herein, “fluid” is meant to include both water (and otherfluids) and oxygen (and other gases) such that “fluid-impervious”includes both water-impervious and oxygen-impervious. Although referredto throughout herein as a “moisture protective layer,” one skilled inthe art based on the disclosure herein will recognize that this layermay be both “moisture protective” and “oxygen protective;” that is, thelayer will protect and insulate the core composition and its contentsfrom both water and oxygen.

When present, the moisture protective layer substantially completelysurrounds the crosslinked polymeric encapsulation layer described above.The moisture protective layer may be utilized when it is desirable toimpart additional water (and/or oxygen) repelling characteristics ontothe microencapsulated heat delivery vehicle. For example, if themicroencapsulated heat delivery vehicle is to be used in a wet wipe, itmay be desirable to utilize a moisture protective layer on top of theencapsulating layer such that the active heating agent is shielded fromthe water contained in the wet wipe solution until the end user rupturesthe microencapsulated heat delivery vehicle at the desired time of useto allow water to contact the heating agent. In the absence of amoisture protective layer, when the microencapsulated heat deliveryvehicle is used in a wet wipe, it may be possible that over time thewater present in the wet wipe solution can diffuse and gain accessthrough the crosslinked encapsulated shell described above and gainaccess to the heating agent causing it to release its heat prematurely.

The moisture protective layer may be present on the microencapsulatedheat delivery vehicle in one layer or in multiple layers. Desirably, themoisture protective layer will be present in from about 1 layer to about30 layers, desirably in from about 1 layer to about 20 layers, and moredesirably in from about 1 layer to about 10 layers to provide furtherprotection. As noted above, the moisture protective layer substantiallycompletely surrounds the encapsulating layer to keep water from reachingthe internal matrix material and ultimately the heating agent. To ensurethe moisture protective layer substantially completely covers theencapsulating layer, multiple layers may be utilized as noted above.Each of the moisture protective layers generally has a thickness of fromabout 1 micrometer to about 200 micrometers, desirably from about 1micrometer to about 100 micrometers, and even more desirably from about1 micrometer to about 50 micrometers.

The moisture protective layer may comprise any number of materialsincluding, for example, polyols in combination with isocynate,styrene-acrylate, vinyl toluene-acrylate, styrene-butadiene,vinyl-acrylate, polyvinyl butyral, polyvinyl acetate, polyethyleneterephthalate, polypropylene, polystyrene, polymethyl methacrylate, polylactic acid, polyvinylidene chloride, polyvinyldichloride, polyethylene,alkyd polyester, carnauba wax, hydrogenated plant oils, hydrogenatedanimal oils, fumed silica, silicon waxes, titanium dioxide, silicondioxide, metals, metal carbonates, metal sulfates, ceramics, metalphosphates, microcrystalline waxes, and combinations thereof.

Generally, the moisture protective layer is present in themicroencapsulated heat delivery vehicle in an amount of from about0.001% (by weight microencapsulated heat delivery vehicle) to about99.8% (by weight microencapsulated heat delivery vehicle), desirablyfrom about 0.1% (by weight microencapsulated heat delivery vehicle) toabout 90% (by weight microencapsulated heat delivery vehicle), moredesirably in an amount of from about 1% (by weight microencapsulatedheat delivery vehicle) to about 75% (by weight microencapsulated heatdelivery vehicle), more desirably in an amount of from about 1% (byweight microencapsulated heat delivery vehicle) to about 50% (by weightmicroencapsulated heat delivery vehicle), and even more desirably in anamount of from about 5% (by weight microencapsulated heat deliveryvehicle) to about 35% (by weight microencapsulated heat deliveryvehicle).

In addition to the moisture protective layer, the microencapsulated heatdelivery vehicle may also optionally include a fugitive layer thatsurrounds the moisture protective layer, if present, or theencapsulating layer if the moisture protective layer is not present. Thefugitive layer can act to stabilize and protect the microencapsulatedheat delivery vehicle from rupturing prematurely due to mechanical load,or can provide other benefits. When present on the microencapsulatedheat delivery vehicle, the fugitive layer can impart strength andwithstand a given mechanical load until a time when the fugitive layeris ruptured by the end user or is decomposed or degraded in apredictable manner in a wet wipe solution, usually during shipmentand/or storage of the product prior to use. Consequently, the fugitivelayer allows the microencapsulated heat delivery vehicle to surviverelatively high mechanical load conditions commonly experienced inshipping and/or manufacturing.

In one embodiment, the fugitive layer substantially completely surroundsthe moisture protective layer (or the encapsulating layer) such thatthere are substantially no access points to the underlying layer.Alternatively, the fugitive layer may be a non-continuous, porous ornon-porous layer surrounding the moisture protective layer (or theencapsulating layer).

The fugitive layer, similar to the moisture protective layer, may bepresent in multiple layers. Specifically, the fugitive layer may bepresent in anywhere from about 1 to about 30 layers, desirably fromabout 1 to about 20 layers, and more desirably from about 1 to about 10layers. Generally, each fugitive layer may have a thickness of fromabout 1 micrometer to about 200 micrometers, desirably from about 1micrometer to about 100 micrometers, and more desirably from about 1micrometer to about 50 micrometers.

The fugitive layer is generally present in the microencapsulated heatdelivery vehicle in an amount of from about 0.001% (by weightmicroencapsulated heat delivery vehicle) to about 99.8% (by weightmicroencapsulated heat delivery vehicle), desirably in an amount of fromabout 0.1% (by weight microencapsulated heat delivery vehicle) to about90% (by weight microencapsulated heat delivery vehicle), more desirablyin an amount of from about 1% (by weight microencapsulated heat deliveryvehicle) to about 80% (by weight microencapsulated heat deliveryvehicle), more desirably in an amount of from about 1% (by weightmicroencapsulated heat delivery vehicle) to about 75% (by weightmicroencapsulated heat delivery vehicle), and even more desirably in anamount of from about 1% (by weight microencapsulated heat deliveryvehicle) to about 50% (by weight microencapsulated heat deliveryvehicle).

The fugitive layer may be comprised of any one of a number of suitablematerials including, for example, polylactic acid, polymers of dextrose,hydrocolloids, alginate, zein, and combinations thereof. Oneparticularly preferred material for use as the fugitive layer is starch.

The microencapsulated heat delivery vehicles as described herein may bemanufactured in any number of ways as discussed below. The first step inthe manufacturing process is generally to coat the desired heat deliveryvehicle (i.e., magnesium chloride) with a hydrophobic wax material asdescribed above prior to incorporating the hydrophobic waxmaterial-coated heating agent into the core composition. As would berecognized by one skilled in the art based on the disclosure herein,this hydrophobic wax material coating of the heating agent step isoptional and can be eliminated if such a coating is not desired and theheating agent is to be incorporated into the core composition withoutany protective coating.

In one embodiment, the hydrophobic wax material is coated onto theheating agent by blending the heating agent and hydrophobic wax materialtogether at an elevated temperature sufficient to melt the hydrophobicwax material in the presence of the heating agent and the melted waxmaterial and heating agent stirred sufficiently to coat the heatingagent. After the coating of the heating agent is complete, the mixtureis allowed to cool to room temperature to allow the wax to solidify onthe heating agent particles. After the coated heating agent particleshave cooled, they can be ground to the desired size prior toincorporation into the matrix material.

After the grinding of the hydrophobic wax material-coated heating agent,it may be desirable to subject the ground material to a further processto ensure that the hydrophobic wax material coating is substantiallycomplete around the heating agents. Suitable additional processesinclude, for example, spheroidization (high heat fluidization slightlybelow the melt temperature of the hydrophobic wax material) and ballmilling. These additional processes can be used to ensure substantiallycomplete coverage of the heating agent with the hydrophobic waxmaterial.

In preparing the microencapsulated heat delivery vehicle, a corecomposition including the hydrophobic wax material-coated (or uncoated)heating agent, an optional encapsulating activator, and surfactant (ifutilized) are first mixed together with the matrix material. This corecomposition is the resulting “core material” inside of the encapsulatinglayer(s), although it will be recognized by one skilled in the art basedon the disclosure herein that the encapsulating activator, if initiallypresent in the core composition, may be substantially or completely usedup in the crosslinking reaction described herein. As will be furtherrecognized by one skilled in the art, some methods of forming an outerlayer on the core composition (i.e., coacervation) may not require achemical encapsulating activator to be present in the core composition,but may utilize a change in pH, a change in temperature, and/or a changein ionic strength of the liquid solution to initiate the formation ofthe encapsulating layer around the core composition. Additionally, itwill be further recognized by one skilled in the art based on thedisclosure herein that the encapsulating activator, when present, may belocated outside of the core composition; that is, the encapsulatingactivator may be located in the liquid solution for example, although itis generally desirable to have it located within the core composition.

The encapsulating activator, when present in the core composition, actsas a crosslinking agent to crosslink the encapsulating layer discussedherein. Once the core composition is introduced into a liquid solutioncontaining a crosslinkable compound as described below, theencapsulating activator interacts with the crosslinkable compound andcauses it to crosslink on the outer surface of the composition to form acrosslinked shell. Because the encapsulating activator chemically reactswith the crosslinkable compound contained in the liquid solution, theresulting microencapsulated heat delivery vehicle may not contain anyencapsulating activator in its final form; or, it may contain a smallamount of encapsulating activator not consumed in the crosslinkingreaction, which in some cases may then act as an additional heatingagent.

The encapsulating activator may be any activator capable of initiating acrosslinking reaction in the presence of a crosslinkable compound.Suitable encapsulating activators include, for example, polyvalent ionsof calcium, polyvalent ions of copper, polyvalent ions of barium,silanes, aluminum, titanates, chelators, acids, and combinationsthereof. Specifically, the encapsulating activator may be calciumchloride, calcium sulfate, calcium oleate, calcium palmitate, calciumstearate, calcium hypophosphite, calcium gluconate, calcium formate,calcium citrate, calcium phenylsulfonate, and combinations thereof. Apreferred encapsulating activator is calcium chloride.

The encapsulating activator is generally present in the core compositionin an amount of from about 0.1% (by weight core composition) to about25% (by weight core composition), desirably from about 0.1% (by weightcore composition) to about 15% (by weight core composition), and stillmore desirably from about 0.1% (by weight core composition) to about 10%(by weight composition).

One skilled in the art will recognize based on the disclosure hereinthat the encapsulating activator may be the same chemical compound asthe heating agent; that is, the same chemical compound may act as boththe encapsulating activator and the heating agent. For example, in oneembodiment, calcium chloride may be added to the composition as bothheating agent and encapsulating activator. When a single compound is tofunction as both heating agent and encapsulating activator, an increasedamount is utilized in the composition to ensure there is sufficientcompound remaining after the crosslinking reaction to function as theheating agent. Of course, if a single compound, such as calciumchloride, is to function as both heating agent and encapsulatingactivator, a portion of the calcium chloride may be surrounded asdescribed herein by a hydrophobic wax material prior to incorporationinto the composition. This protected portion of the dual functioncompound would not be available in this embodiment to act as anencapsulating activator.

To produce the core composition including the matrix material, heatingagent (which may or may not be surrounded by a hydrophobic waxmaterial), encapsulating activator and surfactant (if any), the desiredamounts of these components may be optionally passed through a millingdevice that serves. to thoroughly mix the components together forfurther processing. Suitable wet milling operations include, forexample, bead milling and wet ball milling. Additionally, processesknown to those skilled in the art such as hammer milling and jet millingmay be used to first prepare the heating agent, and then disperse thetreated heating agent into the matrix material containing the surfactantand encapsulating activator followed by thorough mixing.

Once the core composition is prepared, it is introduced into a liquidsolution, generally held at room temperature, to activate a crosslinkingreaction to form an outer encapsulating shell that protects the corecomposition and its components (core material) and allows for immediateuse or further processing. Although described herein primarily inreference to a “crosslinking reaction,” it will be recognized by oneskilled in the art based on the disclosure herein that the encapsulationlayer can be formed around the core composition not only by acrosslinking reaction, but also by coacervation, coagulation,flocculation, adsorbtion, complex coacervation and self-assembly, all ofwhich are within the scope of the present disclosure. As such, the term“crosslinking reaction” is meant to include these other methods offorming the encapsulation layer around the core composition.

One particular advantage of one embodiment described herein is that thepresence of the encapsulating activator in the core composition allowsfor almost instantaneous crosslinking when the core composition isintroduced into the solution containing the crosslinkable compound; thisreduces the potential for unwanted heating agent deactivation. In oneembodiment, the core composition is added dropwise into the liquidcontaining the crosslinkable compound and the beads that form when thedrops contact the liquid are kept separated during the crosslinkingreaction using a sufficient amount of stirring and mixing. It ispreferred to use sufficient stirring and mixing to keep the beadsseparate during the crosslinking reaction to ensure that they remainseparate, individual beads and do not form larger agglomerated massesthat are susceptible to numerous defects. Generally, the drops added tothe liquid solution can have a diameter of from about 0.05 millimetersto about 10 millimeters, desirably from about 1 millimeter to about 3millimeters, and still more desirably from about 0.5 millimeters toabout 1 millimeter. Alternatively, the core composition may beintroduced or poured into the liquid solution including thecrosslinkable compound and then subjected to shear sufficient to breakthe paste into small beads for crosslinking thereon.

In one embodiment, the liquid solution includes a crosslinkable compoundthat can be crosslinked in the presence of the encapsulating activatorto form the outer encapsulate shell. Optionally, a surfactant asdescribed herein can also be introduced into the liquid solution tofacilitate crosslinking. When the core composition including theencapsulating activator is introduced into the liquid containing thecrosslinkable compound, the encapsulating activator migrates to theinterface between the core composition and the liquid solution andinitiates the crosslinking reaction on the surface of the corecomposition to allow the encapsulation layer to grow outward toward theliquid solution. The thickness of the resulting encapsulation layersurrounding the core composition can be controlled by (1) controllingthe amount of encapsulating activator included in the core composition;(2) controlling the amount of time the core composition including theencapsulating activator is exposed to the liquid solution including thecrosslinkable compound; and/or (3) controlling the amount ofcrosslinkable compound in the liquid solution. Generally, anencapsulating layer of sufficient and desired thickness can be formedaround the core composition by allowing the core composition to dwell inthe liquid solution including the crosslinkable compound for from about10 seconds to about 40 minutes, desirably from about 5 minutes to about30 minutes, and still more desirably from about 10 minutes to about 20minutes.

It is generally desirable that the liquid solution containing thecrosslinkable compound has a viscosity suitable for allowing sufficientmixing of the formed beads therein; that is, the viscosity of the liquidsolution should not be so high that stirring and mixing is substantiallyimpaired and the ability to keep the formed beads separated reduced. Tothat end, the liquid solution containing the crosslinkable compoundgenerally contains from about 0.1% (by weight liquid solution) to about50% (by weight liquid solution), desirably from about 0.1% (by weightliquid solution) to about 25% (by weight liquid solution) and moredesirably from about 0.1% (by weight liquid solution) to about 1% (byweight liquid solution) crosslinkable compound.

Any number of crosslinkable compounds can be incorporated into theliquid solution to form the encapsulated layer around the corecomposition upon contact with the encapsulating activator. Some suitablecrosslinkable compounds include, for example, sodium alginate, anionicdispersed latex emulsions, polyacrylic acid, polyvinyl alcohol,polyvinyl acetate, silicates, carbonates, sulfates, phosphates, borates,and combinations thereof. A particularly desirable crosslinkablecompound is sodium alginate.

Once a sufficient amount of time has passed for the encapsulating layerto form on the core composition, the formed beads may be removed fromthe liquid including the crosslinkable compound. The resultingmicroencapsulated heat delivery vehicles may optionally be washedseveral times to remove any crosslinkable compound thereon and dried andare then ready for use or for further processing. One suitable washingliquid is deionized water.

In one embodiment, the microencapsulated heat delivery vehicles formedas described above are subjected to a process to impart a moistureprotective layer thereon that surrounds the encapsulated layer thatcomprises the crosslinked compound. This moisture protective layerprovides the microencapsulated heat delivery vehicle with increasedprotection from water; that is, it makes the microencapsulated heatdelivery vehicle substantially fluid impervious and allows themicroencapsulated heat delivery vehicle to survive long term in anaqueous environment and not degrade until the moisture protective layeris ruptured by mechanical action. The moisture protective layer may be asingle layer applied onto the microencapsulated heat delivery vehicle,or may comprise several layers one on top of the other.

The moisture protective layer may be applied to the microencapsulatedheat delivery vehicle utilizing any number of suitable processesincluding, for example, atomizing or dripping a moisture protectivematerial onto the microencapsulated heat delivery vehicle. Additionally,a Wurster coating process may be utilized. When a solution is used toprovide the moisture protective coating, the solids content of thesolution is generally from about 0.1% (by weight solution) to about 70%(by weight solution), desirably from about 0.1% (by weight solution) toabout 60% (by weight solution), and still more desirably from about 5%(by weight solution) to about 40% (by weight solution). Generally, theviscosity of the solution (at 25° C.) including the moisture protectivematerial is from about 0.6 centipoise to about 10,000 centipoise,desirably from about 20 centipoise to about 400 centipoise, and stillmore desirably from about 20 centipoise to about 100 centipoise.

In one specific embodiment, a fluidized bed process is utilized toimpart the moisture protective layer on the microencapsulated heatdelivery vehicle. The fluidized bed is a bed or layer ofmicroencapsulated heat delivery vehicles through which a stream ofheated or unheated carrier gas is passed at a rate sufficient to set themicroencapsulated heat delivery vehicles in motion and cause them to actlike a fluid. As the vehicles are fluidized, a spray of a solutioncomprising a carrier solvent and the moisture protective material isinjected into the bed and contacts the vehicles imparting the moistureprotective material thereon. The treated vehicles are collected when thedesired moisture protective layer thickness is achieved. Themicroencapsulated heat delivery vehicles can be subjected to one or morefluidized bed processes to impart the desired level of moistureprotective layer. A suitable fluidized bed coating apparatus isillustrated in FIG. 2 wherein the fluidized bed reactor 18 includesheated carrier gas supply 20 , solvent and moisture protective materialsupply 22, and microencapsulated heat delivery vehicles 24 contained inchamber 26. The heated gas and solvent exit the chamber 26 at the top 28of chamber 26.

In another embodiment, the microencapsulated heat delivery vehicle,which may or may not include a moisture protective layer as describedabove, is subjected to a process for imparting a fugitive layer thereonsurrounding the outermost layer. For example, if the microencapsulatedheat delivery vehicle includes a moisture protective layer, the fugitivelayer would be applied on the microencapsulated heat delivery vehiclesuch that it substantially completely covered the moisture protectivelayer. The fugitive layer can be applied in a single layer, or may beapplied in multiple layers.

The fugitive layer may be applied to the microencapsulated heat delivervehicle utilizing any number of suitable processes including, forexample, atomizing or dripping a fugitive material onto themicroencapsulated heat delivery vehicle. When a solution is used toprovide the fugitive coating, the solids content of the solution isgenerally from about 1% (by weight solution) to about 70% (by weightsolution), desirably from about 10% (by weight solution) to about 60%(by weight solution). The pH of the solution is generally from about 2.5to about 11. Generally, the viscosity of the solution (at 25° C.)including the fugitive material is from about 0.6 centipoise to about10,000 centipoise, desirably from about 20 centipoise to about 400centipoise, and still more desirably from about 20 centipoise to about100 centipoise. Similar to the moisture protective layer, a preferredmethod of applying the fugitive layer utilized a fluidized bed reactor.Also, a Wurster coating process may also be used.

In an alternative embodiment of the present disclosure, the heatingagent in the core composition can be combined with one or more otheractive ingredients to impart additional benefits to the end user; thatis, the core composition may comprise two or more active agents. The twoor more active agents may include a heating agent, or may not include aheating agent. Also, the core composition may include a single activeagent that is not a heating agent. Additionally, the active agent orcombination of active agents can be located in one or more of the layerssurrounding the core composition including, for example, in theencapsulation layer, the moisture protective layer, and/or the fugitivelayer. Also, the active agent or combination of active agents can belocated in-between two of the layers on the microencapsulated deliveryvehicle. For example, in one embodiment the microencapsulated deliveryvehicle may include a heating agent in the core composition surroundedby a crosslinked encapsulation layer surrounded by a moisture protectivelayer that includes therein a fragrance oil.

A number of alternative or additional active agents are suitable forinclusion in the core composition. Active agents such as neurosensoryagents (agents that induce a perception of temperature change withoutinvolving an actual change in temperature such as, for examplepeppermint oil, eucalyptol, eucalyptus oil, methyl salicylate, camphor,tea tree oil, ketals, carboxamides, cyclohexanol derivatives, cyclohexylderivatives, and combinations thereof), cleansing agents (e.g., toothhealth agents, enzymes), appearance modifying agents (e.g., toothwhitening agents, exfoliation agents, skin-firming agents, anti-callousagents, anti-acne agents, anti-aging agents, anti-wrinkle agents,anti-dandruff agents, antiperspirant agents, wound care agents, enzymeagents, scar repair agents, colorant agents, humectant agents, hair careagents such as conditioners, styling agents, and detangling agents),powders, skin coloration agents such as tanning agents, lighteningagents, and brightening agents, shine control agents and drugs),nutrients (e.g., anti-oxidants, transdermal drug delivery agents,botanical extracts, vitamins, magnets, magnetic metals, foods, anddrugs), pesticides (e.g., tooth health ingredients, anti-bacterials,anti-virals, anti-fungals, preservatives, insect repellants, anti-acneagents, anti-dandruff agents, anti-parasite agents, wound care agents,and drugs), surface conditioning agents (e.g., pH adjusting agents,moisturizers, skin conditioners, exfoliation agents, shaving lubricants,skin-firming agents, anti-callous agents, anti-acne agents, anti-agingagents, anti-wrinkle agents, anti-dandruff agents, wound care agents,skin lipids, enzymes, scar care agents, humectants, powders, botanicalextracts, and drugs), hair care agents (e.g., shaving lubricants, hairgrowth inhibitors, hair growth promoters, hair removers, anti-dandruffagents, colorant agents, humectants, hair care agents such asconditioners, styling agents, detangling agents, and drugs),anti-inflammatory agents (e.g., tooth health ingredients, skinconditioners, external analgesic agents, anti-irritant agents,anti-allergy agents, anti-inflammatory agents, wound care agents,transdermal drug delivery, and drugs), emotional benefit agents (e.g.,gas generating agents, fragrances, odor neutralizing materials,exfoliation agents, skin-firming agents, anti-callous agents, anti-acneagents, anti-aging agents, soothing agents, calming agents, externalanalgesic agents, anti-wrinkle agents, anti-dandruff agents,antiperspirants, deodorants, wound care agents, scar care agents,coloring agents, powders, botanical extracts and drugs), indicators(e.g., soil indicators), and organisms.

Additional suitable active agents include abrasive materials, abrasiveslurries, acids, adhesives, alcohols, aldehydes, animal feed additives,antioxidants, appetite suppressants, bases, biocides, blowing agents,botanical extracts, candy, carbohydrates, carbon black, carbonlesscopying materials, catalysts, ceramic slurries, chalcogenides,colorants, cooling agents, corrosion inhibitors, curing agents,detergents, dispersants, EDTA, enzymes, exfoliation, fats, fertilizers,fibers, fire retardant materials, flavors, foams, food additives,fragrances, fuels, fumigants, gas forming compounds, gelatin, graphite,growth regulators, gums, herbicides, herbs, spices, hormonal basedcompounds, humectants, hydrides, hydrogels, imaging materials,ingredients that are easily oxidized or not UV stable, inks, inorganicoxides, inorganic salts, insecticides, ion exchange resins, latexes,leavening agents, liquid crystals, lotions, lubricants, maltodextrins,medicines, metals, mineral supplements, monomers, nanoparticles,nematicides, nicotine-based compounds, oil recovery agents, organicsolvents, paint, peptides, pesticides, pet food additives, phase changematerials, phase change oils, pheromones, phosphates, pigments, dyes,plasticizers, polymers, propellants, proteins, recording materials,silicates, silicone oils, stabilizers, starches, steroids, sugars,surfactants, suspensions, dispersions, emulsions, vitamins, warmingmaterials, waste treatment materials, adsorbents, water insoluble salts,water soluble salts, water treatment materials, waxes, and yeasts.

As noted herein, one or more of these additional active ingredients canbe used in place of the heating agent in the microencapsulated deliveryvehicle; that is, the active ingredient can be an active ingredientother than a heating agent.

One particular active agent that can be used in place of a heating agentas the active material in the microencapsulated delivery vehicle is acooling agent. In many situations it may be beneficial to provide aproduct that is capable of providing a cooling sensation on the skin tosoothe and relieve skin irritation, or to relax muscles. Some situationsthat may require a cooling sensation on the skin include, for example,sore muscles, sunburned skin, skin over-heated from exercise,hemorrhoids, minor scrapes and burns, and the like. Specific productsthat may include a cooling agent include, for example, spa gloves andsocks, foot creams and wraps, cooling moist bath tissue, topicalanalgesics, cooling lotions, cooling acne cloths, sunburn relief gelsand creams, cooling suntan lotions, cooling insect bite relief spraysand/or lotions, cooling diaper rash creams, coolinganti-irritation/anti-inflammatory creams, and cooling eye patches.

Suitable cooling agents are chemical compounds that have a negative heatof solution; that is, suitable cooling agents are chemical compoundsthat when dissolved in water feel cool due to an endothermic chemicalreaction. Some suitable cooling agents for inclusion in themicroencapsulated heat delivery vehicle include, for example, ammoniumnitrate, sodium chloride, potassium chloride, xylitol, barium hydroxide(Ba(OH)₂.8H₂O), barium oxide (BaO.9H₂O), magnesium potassium sulfate(MgSO₄.K₂SO₄.6H₂O), potassium aluminum sulfate (KAl(SO₄)₂.12H₂O), sodiumborate (tetra) (Na₂B₄O₇. 10H₂O), sodium phosphate (Na₂HPO₄.12H₂O), andcombinations thereof. Similar to the heating agents described herein, insome embodiments, the cooling agent may be surrounded by a hydrophobicwax material prior to being incorporated into the matrix material.

As noted above, the microencapsulated heat (or other active agent, suchas a cooling agent, for example, alone or in combination with a heatingagent) delivery vehicles as described herein are suitable for use in anumber of products, including wipe products, wraps, such as medicalwraps and bandages, headbands, wristbands, helmet pads, personal careproducts, cleansers, lotions, emulsions, oils, ointments, salves, balms,and the like. Although described primarily herein in relation the wipes,it will be recognized by one skilled in the art that themicroencapsulated delivery vehicles described herein could beincorporated into any one or more of the other products listed above.

Generally, the wipes of the present disclosure including themicroencapsulated heat delivery vehicles can be wet wipes or dry wipes.As used herein, the term “wet wipe” means a wipe that includes greaterthan about 70% (by weight substrate) moisture content. As used herein,the term “dry wipe” means a wipe that includes less than about 10% (byweight substrate) moisture content. Specifically, suitable wipes for usein the present disclosure can include wet wipes, hand wipes, face wipes,cosmetic wipes, household wipes, industrial wipes, and the like.Particularly preferred wipes are wet wipes, and other wipe-types thatinclude a solution.

Materials suitable for the substrate of the wipes are well know to thoseskilled in the art, and are typically made from a fibrous sheet materialwhich may be either woven or nonwoven. For example, suitable materialsfor use in the wipes may include nonwoven fibrous sheet materials whichinclude meltblown, coform, air-laid, bonded-carded web materials,hydroentangled materials, and combinations thereof. Such materials canbe comprised of synthetic or natural fibers, or a combination thereof.Typically, the wipes of the present disclosure define a basis weight offrom about 25 grams per square meter to about 120 grams per square meterand desirably from about 40 grams per square meter to about 90 grams persquare meter.

In one particular embodiment, the wipes of the present disclosurecomprise a coform basesheet of polymer fibers and absorbent fibershaving a basis weight of from about 60 to about 80 grams per squaremeter and desirably about 75 grams per square meter. Such coformbasesheets are manufactured generally as described in U.S. Pat. Nos.4,100,324, issued to Anderson, et al. (Jul. 11, 1978); 5,284,703, issuedto Everhart, et al. (Feb. 8, 1994); and 5,350,624, issued to Georger, etal. (Sep. 27, 1994), which are incorporated by reference to the extentto which they are consistent herewith. Typically, such coform basesheetscomprise a gas-formed matrix of thermoplastic polymeric meltblown fibersand cellulosic fibers. Various suitable materials may be used to providethe polymeric meltblown fibers, such as, for example, polypropylenemicrofibers. Alternatively, the polymeric meltblown fibers may beelastomeric polymer fibers, such as those provided by a polymer resin.For instance, Vistamaxx® elastic olefin copolymer resin designatedPLTD-1810, available from ExxonMobil Corporation (Houston, Tex.) orKRATON G-2755, available from Kraton Polymers (Houston, Tex.) may beused to provide stretchable polymeric meltblown fibers for the coformbasesheets. Other suitable polymeric materials or combinations thereofmay alternatively be utilized as known in the art.

As noted above, the coform basesheet additionally may comprise variousabsorbent cellulosic fibers, such as, for example, wood pulp fibers.Suitable commercially available cellulosic fibers for use in the coformbasesheets can include, for example, NF 405, which is a chemicallytreated bleached southern softwood Kraft pulp, available fromWeyerhaeuser Co. of Federal Way (Wash.); NB 416, which is a bleachedsouthern softwood Kraft pulp, available from Weyerhaeuser Co.; CR-0056,which is a fully debonded softwood pulp, available from Bowater, Inc.(Greenville, S.C.); Golden Isles 4822 debonded softwood pulp, availablefrom Koch Cellulose (Brunswick, Ga.); and SULPHATATE HJ, which is achemically modified hardwood pulp, available from Rayonier, Inc. (Jesup,Ga.).

The relative percentages of the polymeric meltblown fibers andcellulosic fibers in the coform basesheet can vary over a wide rangedepending upon the desired characteristics of the wipes. For example,the coform basesheet may comprise from about 10 weight percent to about90 weight percent, desirably from about 20 weight percent to about 60weight percent, and more desirably from about 25 weight percent to about35 weight percent of the polymeric meltblown fibers based on the dryweight of the coform basesheet being used to provide the wipes.

In an alternative embodiment, the wipes of the present disclosure cancomprise a composite which includes multiple layers of materials. Forexample, the wipes may include a three layer composite which includes anelastomeric film or meltblown layer between two coform layers asdescribed above. In such a configuration, the coform layers may define abasis weight of from about 15 grams per square meter to about 30 gramsper square meter and the elastomeric layer may include a film materialsuch as a polyethylene metallocene film. Such composites aremanufactured generally as described in U.S. Pat. No. 6,946,413, issuedto Lange, et al. (Sep. 20, 2005), which is hereby incorporated byreference to the extent it is consistent herewith.

In accordance with the present disclosure, the contents (i.e., heatingagent) of the microencapsulated heat delivery vehicle as describedherein are capable of generating heat to produce a warming sensation inthe wipe upon being activated (i.e., ruptured) and wetted. In oneembodiment, the wipe is a wet wipe comprising a wetting solution inaddition to the fibrous sheet material and the microencapsulated heatdelivery vehicle. When the microencapsulated heat delivery vehicle isruptured, its contents contact the wetting solution of the wet wipe, andan exothermic reaction occurs, thereby warming the wipe. The wettingsolution can be any wetting solution known to one skilled in the wetwipe art. Generally, the wetting solution can include water, emollients,surfactants, preservatives, chelating agents, pH adjusting agents, skinconditioners, fragrances, and combinations thereof. For example, onesuitable wetting solution for use in the wet wipe of the presentdisclosure comprises about 98% (by weight) water, about 0.6% (by weight)surfactant, about 0.3% (by weight) humectant, about 0.3% (by weight)emulsifier, about 0.2% (by weight) chelating agent, about 0.35% (byweight) preservative, about 0.002% (by weight) skin conditioning agent,about 0.03% (by weight) fragrance, and about 0.07% (by weight) pHadjusting agent. One specific wetting solution suitable for use in thewet wipe of the present disclosure is described in U.S. Pat. No.6,673,358, issued to Cole et al. (Jan. 6, 2004), which is incorporatedherein by reference to the extent it is consistent herewith.

In another embodiment, the wipe is a dry wipe. In this embodiment, thewipe can be wetted with an aqueous solution just prior to, or at thepoint of, use of the wipe. The aqueous solution can be any aqueoussolution known in the art to be suitable for use in wipe products.Generally, the aqueous solution includes mainly water, and can furtherinclude additional components, such as cleansers, lotions,preservatives, fragrances, surfactants, emulsifiers, and combinationsthereof. Once the wipe is wetted with the aqueous solution and thecontents of the microencapsulated heat delivery vehicle contact theaqueous solution, an exothermic reaction similar to the wet wipeembodiment above is produced, thereby warming the wipe.

It has been determined that the ideal temperature for a wipe to beutilized is a temperature of from about 30° C. to about 40° C. (86°F.-104° F.). A conventional wipe will typically be stored at roomtemperature (about 23° C. (73.4° F.). As such, when themicroencapsulated heat delivery vehicle ruptures, and releases itscontents, and the contents contact an aqueous solution, a warmingsensation is produced, increasing the temperature of the solution andwipe by at least about 5° C. More suitably, the temperature of thesolution and wipe is increased by at least about 10° C., even moresuitably, increased by at least about 15° C., and even more suitablyincreased by at least about 20° C. or more.

Generally, the elapsed time between the dispensing of a wipe product anduse of the product is about 2 seconds or less, and typically is about 6seconds or less. As such, once the microencapsulated heat deliveryvehicle of the present disclosure is ruptured and its contents contactedby water, the contents of the microencapsulated heat delivery vehiclebegin to generate heat and a warming sensation is suitably perceived inless than about 20 seconds. More suitably, the warming sensation isperceived in less than about 10 seconds, even more suitably, in lessthan about 5 seconds, and even more suitably, in less than about 2seconds.

Additionally, once the warming sensation begins, the warming sensationof the wipe product is suitably maintained for at least about 5 seconds.More suitably, the warming sensation is maintained for at least about 8seconds, even more suitably for at least about 15 seconds, even moresuitably for at least about 20 seconds, even more suitably for at leastabout 40 seconds, and even more suitably for at least about 1 minute.

To generate the temperature increase described above, the wipes of thepresent disclosure suitably comprise from about 0.33 grams per squaremeter to about 500 grams per square meter microencapsulated heatdelivery vehicle. More suitably, the wipes comprise from about 6.0 gramsper square meter to about 175 grams per square meter microencapsulatedheat delivery vehicle, even more suitably from about 16 grams per squaremeter to about 90 grams per square meter, and even more suitably, fromabout 30 grams per square meter to about 75 grams per square metermicroencapsulated heat delivery vehicle.

The microencapsulated heat delivery vehicle can be applied to the wipeusing any means known to one skilled in the art. Preferably, themicroencapsulated heat delivery vehicle is embedded into the core of thefibrous sheet material of the wipe. By embedding the microencapsulatedheat delivery vehicle into the core of the fibrous sheet material, thewipe will have a reduced grittiness feel because of a cushion effect andthe ruptured shells of the microencapsulated heat delivery vehicle willnot come into direct contact with the user's skin. Additionally, whenthe microencapsulated heat delivery vehicle is located in the core ofthe fibrous sheet material, the microencapsulated heat delivery vehicleis better protected from premature heat release caused by the conditionsof manufacturing, storage, and transportation of the wipe.

In one embodiment, the microencapsulated heat delivery vehicle isembedded inside of the fibrous sheet material. For example, in onespecific embodiment, the fibrous sheet material is one or more meltblownlayers made by providing a stream of extruded molten polymeric fibers.To incorporate the microencapsulated heat delivery vehicles, a stream ofmicroencapsulated heat delivery vehicles can be merged with the streamof extruded molten polymeric fibers and collected on a forming surfacesuch as a forming belt or forming drum to form the wipe comprising themicroencapsulated heat delivery vehicle. Optionally, a forming layer canbe placed on the forming surface and used to collect themicroencapsulated heat delivery vehicles in the wipe. By using thismethod, the microencapsulated heat delivery vehicle is mechanicallyentrapped within the forming layer.

The stream of meltblown polymeric fibers may be provided by meltblowinga copolymer resin or other polymer. For example, in one embodiment, themelt temperature for a copolymer resin such as Vistamaxx® PLTD 1810 canbe from about 450° F. (232° C.) to about 540° F. (282° C.). As notedabove, suitable techniques for producing nonwoven fibrous webs, whichinclude meltblown fibers, are described in the previously incorporatedU.S. Pat. Nos. 4,100,324 and 5,350,624. The meltblowing techniques canbe readily adjusted in accordance with the knowledge of one skilled inthe art to provide turbulent flows that can operatively intermix thefibers and the microencapsulated heat delivery vehicles. For example,the primary air pressure may be set at 5 pounds per square inch (psi)and the meltblown nozzles may be 0.020 inch spinneret hole nozzles.

Additionally, immediately following the formation of the meltblownstructure, the meltblown polymeric fibers can be tacky, which can beadjusted to provide additional adhesiveness between the fibers and themicroencapsulated heat delivery vehicles.

In another embodiment, the fibrous sheet material is a coform basesheetcomprising a matrix of thermoplastic polymeric meltblown fibers andabsorbent cellulosic fibers. Similar to the meltblown embodiment above,when the fibrous sheet material is a matrix of thermoplastic polymericmeltblown fibers and absorbent cellulosic fibers, a stream ofmicroencapsulated heat delivery vehicles can be merged with a stream ofcellulosic fibers and a stream of polymeric fibers into a single streamand collected on a forming surface such as a forming belt or formingdrum to form a wipe comprising a fibrous sheet material with themicroencapsulated heat delivery vehicles within its core.

The stream of absorbent cellulosic fibers may be provided by feeding apulp sheet into a fiberizer, hammermill, or similar device as is knownin the art. Suitable fiberizers are available from Hollingsworth(Greenville, S.C.) and are described in U.S. Pat. No. 4,375,448, issuedto Appel, et al. (Mar. 1, 1983), which is incorporated by reference tothe extent to which it is consistent herewith. The stream of polymericfibers can be provided as described above.

The thickness of the fibrous sheet material will typically depend uponthe diameter size of the microencapsulated heat delivery vehicle, thefibrous sheet material basis weight, and the microencapsulated heatdelivery vehicle loading. For example, as the size of themicroencapsulated heat delivery vehicle is increased, the fibrous sheetmaterial must be thicker to prevent the wipe from having a gritty feel.

In another embodiment, the fibrous sheet material is made up of morethan one layer. For example, when the fibrous sheet material is ameltblown material, the fibrous sheet material can suitably be made upof two meltblown layers secured together, more suitably three meltblownlayers, even more suitably four meltblown layers, and even more suitablyfive or more meltblown layers. When the fibrous sheet material is acoform basesheet, the fibrous sheet material can suitably be made up oftwo coform basesheet layers secured together, more suitably three coformbasesheet layers, even more suitably four coform basesheet layers, evenmore suitably five or more coform basesheet layers. Moreover, when thefibrous sheet material includes a film, the fibrous sheet material cansuitably be made up of two film layers, more suitably three film layers,even more suitably four film layers, and even more suitably five or morefilm layers. In one embodiment, the layers are separate layers. Inanother embodiment, the layers are plied together.

Using the additional layers will allow for improved capture of themicroencapsulated heat delivery vehicle. This helps to ensure themicroencapsulated heat delivery vehicle will remain in the wipe duringshipping and storage. Additionally, as the microencapsulated heatdelivery vehicle becomes further entrapped in the fibrous sheetmaterial, the grittiness of the wipe is reduced.

To incorporate the microencapsulated heat delivery vehicle in betweenthe layers of fibrous sheet material, the microencapsulated heatdelivery vehicle is sandwiched between a first layer and a second layerof the fibrous sheet material, and the layers are then laminatedtogether using any means known in the art. For example, the layers canbe secured together thermally or by a suitable laminating adhesivecomposition.

Thermal bonding includes continuous or discontinuous bonding using aheated roll. Point bonding is one suitable example of such a technique.Thermal bonds should also be understood to include various ultrasonic,microwave, and other bonding methods wherein the heat is generated inthe non-woven or the film.

In a preferred embodiment, the first layer and second layer arelaminated together using a water insoluble adhesive composition.Suitable water insoluble adhesive compositions can include hot meltadhesives and latex adhesives as described in U.S. Pat. Nos. 6,550,633,issued to Huang, et al. (Apr. 22, 2003); 6,838,154, issued to Anderson,et al. (Oct. 25, 2005); and 6,958,103, issued to Varona et al. (Jan. 4,2005), which are hereby incorporated by reference to the extent they areconsistent herewith. Suitable hot melt adhesives can include, forexample, RT 2730 APAO and RT 2715 APAO, which are amorphouspolyalphaolefin adhesives (commercially available from Huntsman PolymersCorporation, Odessa, Tex.) and H2800, H2727A, and H2525A, which are allstyrenic block copolymers (commercially available from Bostik Findley,Inc., Wauwatosa, Wis.). Suitable latex adhesives include, for example,DUR-O-SET E-200 (commercially available from National Starch andChemical Co., Ltd., Bridgewater, N.J.) and Hycar 26684 (commerciallyavailable from B. F. Goodrich, Laval, Quebec).

The water insoluble adhesive composition can additionally be used incombination with the microencapsulated heat delivery vehicle between thefirst and second layers of the fibrous sheet material. The waterinsoluble adhesive composition will provide improved binding of themicroencapsulated heat delivery vehicle to the first and second layersof the fibrous sheet material. Typically, the adhesive composition canbe applied to the desired area by spraying, knifing, roller coating, orany other means suitable in the art for applying adhesive compositions.

Suitably, the adhesive composition can be applied to the desired area ofthe wipe in an amount of from about 0.01 grams per square meter to about20 grams per square meter. More suitably, the adhesive composition canbe applied in an amount of from about 0.05 grams per square meter toabout 0.5 grams per square meter.

In yet another embodiment, the microencapsulated heat delivery vehiclemay be distributed within a pocket of the fibrous sheet material.Similar to the pattern distribution method described herein below, thepockets of microencapsulated heat delivery vehicles provide for atargeted warming sensation in the wipe.

As an alternative to embedding the microencapsulated heat deliveryvehicles into the core of the fibrous sheet material, themicroencapsulated heat delivery vehicles can be deposited on the outersurface of the fibrous sheet material. In one embodiment, themicroencapsulated heat delivery vehicles are deposited on one outersurface of the fibrous sheet material. In another embodiment, themicroencapsulated heat delivery vehicles are deposited on both outersurfaces of the fibrous sheet material.

To provide for better attachment of the microencapsulated heat deliveryvehicles to the outer surface of the fibrous sheet material, a waterinsoluble adhesive composition can be applied with the microencapsulatedheat delivery vehicles onto the outer surface of the fibrous sheetmaterial. Suitable water insoluble adhesive compositions are describedherein above. Suitably, the adhesive composition can be applied to theouter surface of the fibrous sheet material in an amount of from about0.01 grams per square meter to about 20 grams per square meter. Moresuitably, the adhesive composition can be applied in an amount of fromabout 0.05 grams per square meter to about 0.5 grams per square meter.

The microencapsulated heat delivery vehicles may be embedded in ordistributed on the fibrous sheet material in a continuous layer or apatterned layer. By using a patterned layer, a targeted warmingsensation can be achieved. These methods of distribution canadditionally reduce manufacturing costs as reduced amounts ofmicroencapsulated heat delivery vehicles are required. Suitably, themicroencapsulated heat delivery vehicles can be distributed in patternsincluding, for example, characters, an array of separate lines, swirls,numbers, or dots of microencapsulated heat delivery vehicles. Continuouspatterns, such as stripes or separate lines that run parallel with themachine direction of the web, are particularly preferred as thesepatterns may be more process-friendly.

Additionally, the microencapsulated heat delivery vehicles may becolored using a coloring agent prior to applying the microencapsulatedheat delivery vehicles to the fibrous sheet material. The coloring ofthe microencapsulated heat delivery vehicles can improve the aestheticsof the wipe. Additionally, in embodiments where targeted warming isdesired, the coloring of the microencapsulated heat delivery vehiclescan direct the consumer of the wipe product to the location of themicroencapsulated heat delivery vehicles in the wipe.

Suitable coloring agents include, for example, dyes, color additives,and pigments or lakes. Suitable dyes include, for example, Blue 1, Blue4, Brown 1, External Violet 2, External Violet 7, Green 3, Green 5,Green 8, Orange 4, Orange 5, Orange 10, Orange 11, Red 4, Red 6, Red 7,Red 17, Red 21, Red 22, Red 27, Red 28, Red 30, Red 31, Red 33, Red 34,Red 36, Red 40, Violet 2, Yellow 5, Yellow 6, Yellow 7, Yellow 8, Yellow10, Yellow 11, Acid Red 195, Anthocyanins, Beetroot Red, BromocresolGreen, Bromothymol Blue, Capsanthin/Capsorubin, Curcumin, andLactoflavin. Also, many dyes found suitable for use in the EuropeanUnion and in Japan may be suitable for use as coloring agents in thepresent disclosure.

Suitable color additives include, for example, aluminum powder, annatto,bismuth citrate, bismuth oxychloride, bronze powder, caramel, carmine,beta carotene, chloraphyllin-copper complex, chromium hydroxide green,chromium oxide greens, copper powder, disodium EDTA-copper, ferricammonium ferrocyanide, ferric ferrocyanide, guauazulene, guanine, henna,iron oxides, lead acetate, manganese violet, mica, pyrophylite, silver,titanium dioxide, ultramarines, zinc oxide, and combinations thereof.

Suitable pigments or lakes include, for example, Blue 1 Lake, ExternalYellow 7 Lake, Green 3 Lake, Orange 4 Lake, Orange 5 Lake, Orange 10Lake, Red 4 Lake, Red 6 Lake, Red 7 Lake, Red 21 Lake, Red 22 Lake, Red27 Lake, Red 28 Lake, Red 30 Lake, Red 31 Lake, Red 33 Lake, Red 36Lake, Red 40 Lake, Yellow 5 Lake, Yellow 6 Lake, Yellow 7 Lake, Yellow10 Lake, and combinations thereof.

Any means known to one of skill in the art capable of producingsufficient force to break the capsules can be used in the presentdisclosure. In one embodiment, the microencapsulated heat deliveryvehicles can be broken by the user at the point of dispensing the wipefrom a package. For example, a mechanical device located inside of thepackage containing the wipes can produce a rupture force sufficient torupture the capsules upon dispensing the wipe, thereby exposing thecontents of the microencapsulated heat delivery vehicles.

In another embodiment, the capsules can be broken by the user just priorto or at the point of use of the wipe. By way of example, in oneembodiment, the force produced by the hands of the user of the wipe canbreak the capsules, exposing the contents of the microencapsulated heatdelivery vehicles.

Under certain conditions, such as in high ambient temperatureconditions, the self-warming wipes of the present disclosure may beperceived by the user as uncomfortably warm. Conversely, theself-warming wipe may begin cooling prior to the end use of the wipe.Since the self-warming wipes are manufactured to provide a designatedtemperature rise, one or more phase change materials may optionally beincluded in the wipe to provide thermal stability to the wipe when thewipe is subjected to extreme heat.

The phase change materials use their heat of fusion to automaticallyregulate the temperature of the self-warming wipe. As well known in theart, “heat of fusion” is the heat in joules required to convert 1.0 gramof a material from its solid form to its liquid form at its meltingtemperature. Accordingly, if the contents of the microencapsulated heatdelivery vehicle are activated and the temperature of the wipe reachesor exceeds the melting point of the phase change material, the phasechange material will liquefy, thereby absorbing the heat from the wipe.Once the wipe begins to cool, the phase change material will resolidifyby releasing the absorbed heat. In one embodiment, to provide thermalstability to the wipe, the phase change material can suitably liquefyand resolidify for one cycle. In another embodiment, such as duringtransportation where the temperature of the wipe can fluctuate, thephase change material undergoes multiple cycles of liquefying andresolidifying.

Suitably, the wipes of the present disclosure may comprise one or morephase change materials for regulating the temperature of the wipe. Inone specific embodiment, the wipe comprises a first phase changematerial. In another embodiment, the wipe comprises a first phase changematerial and a second phase change material.

As noted above, the ideal temperature for the wipes of the presentdisclosure is a temperature of from about 30° C. to about 40° C. (86°F.-104° F.). As such, suitable phase change materials for use as thefirst phase change material have a melting point of from about 22° C. toabout 50° C. More suitably, the first phase change material has amelting point of from about 30° C. to about 40° C., and even moresuitably about 35° C.

Additionally, the first phase change materials have a heat of fusionsuitable for regulating the temperature of the self-warming wipes of thepresent disclosure. Suitably, the first phase change materials have aheat of fusion of from about 8.0 joules/gram to about 380 joules/gram.More suitably, the first phase change materials have a heat of fusion offrom about 100 joules/gram to about 380 joules/gram.

Suitable materials for use as the first phase change materials include,for example, n-Tetracosane, n-Tricosane, n-Docosane, n-Heneicosane,n-Eicosane, n-Nonadecane, n-Octadecane, n-Heptadecane, and combinationsthereof.

In one embodiment, a second phase change material can be included toprovide additional protection against the wipe becoming too hot. Thesecond phase change material is different than the first phase changematerial. For example, the second phase change material typically has ahigher melting point as compared to the first phase change material. Byhaving a higher melting point, the second phase change materials arecapable of absorbing heat at a higher temperature level, and as such canprovide improved protection against thermal discomfort of the skin.Specifically, the second phase change materials suitably have a meltingpoint of from about 50° C. to about 65° C., more suitably, from about50° C. to about 60° C.

Suitable materials for the second phase change materials include, forexample, n-Octacosane, n-Heptacosane, n-Hexacosane, n-Pentacosane, andcombinations thereof.

Any of the phase change materials described above can be introduced intothe wipe in solid or liquid form. For example, in one embodiment, thephase change materials are in solid powder form or particles. Suitably,the phase change material particles have a particle size of from about1.0 micrometers to about 700 micrometers. More suitably, the phasechange material particles have a particle size of from about 300micrometers to about 500 micrometers.

In one embodiment, the phase change material particles can bemicroencapsulated. Generally, the phase change material particles can bemicroencapsulated using any method known in the art. In one preferredembodiment, the phase change material particles are microencapsulatedusing the alginate encapsulation method described above for themicroencapsulated heat delivery vehicles. In another embodiment, thephase change material particles are microencapsulated using the fluidbed coating described above for the microencapsulated heat deliveryvehicles. Other suitable means of encapsulating the phase changematerial particles can include, for example, pan coating, annular-jetencapsulation, complex coacervation, spinning-disk coating, andcombinations thereof.

The microencapsulation shell thickness may vary depending upon the phasechange material utilized, and is generally manufactured to allow theencapsulated phase change material particle to be covered by a thinlayer of encapsulation material, which may be a monolayer or thickerlaminate layer, or may be a composite layer. The microencapsulationlayer should be thick enough to resist cracking or breaking of the shellduring handling or shipping of the product. The microencapsulation layershould also be constructed such that atmospheric conditions duringmanufacturing, storage, and/or shipment will not cause a breakdown ofthe microencapsulation layer and result in a release of the phase changematerial.

In another embodiment, the phase change material is in liquid form,specifically, in a liquid coating composition. To produce the liquidcoating composition, the phase change material, preferably in a purepowder form is combined with an aqueous solution. The solution is thenheated to a temperature above the phase change material melting pointand stirred to shear the phase change material to form the liquidcoating composition comprising the liquid phase change material. In onespecific embodiment, the aqueous solution can be the wetting solution ofa wet wipe described herein above.

In one embodiment, once the liquid coating composition is applied to thefibrous sheet material of the wipe, the composition dries and the phasechange materials solidify into small particles that are distributedthroughout the fibrous sheet material of the wipe.

The liquid coating composition may optionally comprise additionalcomponents to improve the properties, such as spreadability andadhesiveness, of the composition. For example, in one embodiment, theliquid coating composition can comprise a tackifier. Using a tackifierwill improve the binding of the liquid coating composition, and inparticular the phase change material, to the fibrous sheet material.

Typically, the phase change material can be embedded inside of thefibrous sheet material or deposited onto the outer surface of thefibrous sheet material. In one embodiment, the phase change material isembedded inside of the fibrous sheet material. The phase change materialcan be embedded into the core of the fibrous sheet material using anymethod described above for embedding the microencapsulated heat deliveryvehicles into the core.

In another embodiment, the phase change material can be deposited on anouter surface of the fibrous sheet material. Typically, the phase changematerial can be deposited on an outer surface of the fibrous sheetmaterial using any method described above for depositing themicroencapsulated heat delivery vehicles on an outer surface of thefibrous sheet material. Similar to the microencapsulated heat deliveryvehicles, when depositing the phase change material, the phase changematerial can be deposited on one outer surface of the fibrous sheetmaterial, or the phase change material can be applied to both outersurfaces of the fibrous sheet material.

In addition to the methods of application described above, the phasechange materials described herein can be applied to the desired area ofthe fibrous sheet material using the methods of spray coating, slotcoating and printing, or a combination thereof. In slot coating, thephase change material is introduced directly onto or into the desiredarea of the fibrous sheet material in “slots,” discrete row patterns, orother patterns. Similar to applying the microencapsulated heat deliveryvehicle in patterns described above, slot coating may be advantageous incertain applications where it is not desirable to coat the entirefibrous sheet material with a phase change material.

The phase change material should suitably be applied to the fibroussheet material similar to the microencapsulated heat delivery vehicle.Specifically, when the microencapsulated heat delivery vehicle isapplied in a continuous layer, the phase change material should beapplied in a continuous layer. Likewise, when the microencapsulated heatdelivery vehicle is applied in a patterned layer, the phase changematerial should be applied in a patterned layer. Suitable patterns forapplying the phase change materials are those patterns described abovefor the microencapsulated heat delivery vehicles. Specifically, thephase change materials can be applied in the patterns including, forexample, stripes, characters, swirls, numbers, dots, and combinationsthereof. Applying the phase change material in a similar manner as themicroencapsulated heat delivery vehicle will allow for the phase changematerial to more easily and efficiently absorb the heat generated by themicroencapsulated heat delivery vehicle, thus, providing betterprotection against thermal discomfort to the user of the wipe.

The amount of phase change material to be applied to the fibrous sheetmaterial will depend upon the desired temperature increase of the wipe,the type of microencapsulated heat delivery vehicle used, the amount ofmicroencapsulated heat delivery vehicle used, and the type of phasechange material used. In one embodiment, when all of the heat generatedby the heating agent is absorbed by the wipe, the formula forcalculating the amount of phase change material required for use in thewipe is as follows:m _((PCM)) =[ΔH _((HA)) ×m _((HA)) ]/ΔH _((PCM))wherein m_((PCM)) is the required mass of phase change material;ΔH_((HA)) is the heat of solution or the heat generated by themicroencapsulated heat delivery vehicle, per unit mass; m_((HA)) is themass of the microencapsulated heat delivery vehicle used; and ΔH_((PCM))is the heat of fusion of the phase change material, per unit mass.

As noted above, in one specific embodiment, the microencapsulated heatdelivery vehicles as described herein are suitable for combination witha biocide agent for use in cleansing compositions, which may be usedalone, or in combination with a cleansing product such as a wipe.Generally, the cleansing composition includes the microencapsulated heatdelivery vehicle as described above and a biocide agent and is suitablefor cleaning both animate and inanimate surfaces.

Using the microencapsulated heat delivery vehicles in the cleansingcomposition in combination with the biocide agents results in anincreased biocidal effect when the microencapsulated heat deliveryvehicles are activated. Specifically, the increase in temperature hasbeen found to activate or enhance the function of the biocide agentspresent in the cleansing composition.

Generally, the three main factors affecting the efficacy of biocideagents include: (1) mass transfer of biocide agents in the cleansingcomposition to the microbe-water interface; (2) chemisorption of biocideagents to the cell wall or cell membrane of the microbes; and (3)diffusion of the activated chemisorbed biocide agent into the cell ofthe microbe. It has been found that temperature is a primary regulatorof all three factors. For example, the lipid bilayer cell membranestructure of many microbes “melts” at higher than room temperatures,allowing holes to form in the membrane structure. These holes can allowthe biocide agent to more easily diffuse through the microbe cell wallor membrane and enter the cell.

Generally, the cleansing compositions of the present disclosure arecapable of killing or substantially inhibiting the growth of microbes.Specifically, the biocide agent of the cleansing compositions interfaceswith either the reproductive or metabolic pathways of the microbes tokill or inhibit the growth of the microbes.

Microbes suitably affected by the biocide agents of the cleansingcomposition include viruses, bacteria, fungi, and protozoans. Virusesthat can be affected by the biocide agents include, for example,Influenza, Parainfluenza, Rhinovirus, Human Immunodeficiency Virus,Hepatitis A, Hepatitis B, Hepatitis C, Rotavirus, Norovirus, Herpes,Coronavirus, and Hanta virus. Both gram positive and gram negativebacteria are affected by the biocide agents of the cleansingcomposition. Specifically, bacteria affected by the biocide agents usedin the cleansing compositions include, for example, Staphylococcusaureus, Streptococcus pneumoniae, Streptococcus pyogenes, Pseudomonasaeruginose, Klebsiella pneumoniae, Escherichia coli, Enterobacteraerogenes, Enterococcus faecalis, Bacillus subtilis, Salmonella typhi,Mycobacterium tuberculosis, and Acinetobacter baumannii. Fungi affectedby the biocide agents include, for example, Candida albicans,Aspergillus niger, and Aspergillus fumigates. Protozoans affected by thebiocide agents include, for example, cyclospora cayetanensis,Cryptosporidum parvum, and species of microsporidum.

Suitable biocide agents for use in the cleansing compositions include,for example, isothiazolones, alkyl dimethyl ammonium chloride,triazines, 2-thiocyanomethylthio benzothiazol, methylene bisthiocyanate, acrolein, dodecylguanidine hydrochloride, chlorophenols,quarternary ammonium salts, gluteraldehyde, dithiocarbamates,2-mercaptobenzothiazole, para-chloro-meta-xylenol, silver,chlorohexidine, polyhexamethylene biguanide, n-halamines, triclosan,phospholipids, alpha hydroxyl acids, 2,2-dibromo-3-nitrilopropionamide,2-bromo-2-nitro-1,3-propanediol, farnesol, iodine, bromine, hydrogenperoxide, chlorine dioxide, alcohols, ozone, botanical oils (e.g., teetree oil and rosemary oil), botanical extracts, benzalkonium chloride,chlorine, sodium hypochlorite, and combinations thereof.

The cleansing compositions of the present disclosure may also optionallycontain a variety of other components which may assist in providing thedesired cleaning properties. For example, additional components mayinclude non-antagonistic emollients, surfactants, preservatives,chelating agents, pH adjusting agents, fragrances, moisturizing agents,skin benefit agents (e.g., aloe and vitamin E), antimicrobial actives,acids, alcohols, or combinations or mixtures thereof. The compositionmay also contain lotions, and/or medicaments to deliver any number ofcosmetic and/or drug ingredients to improve performance.

The cleansing compositions of the present disclosure are typically insolution form and include water in an amount of about 98% (by weight).The solution can suitably be applied alone as a spray, lotion, foam, orcream.

When used as a solution, the biocide agents are typically present in thecleansing composition in an amount of from about 3.0×10⁻⁶% (by weight)to about 95% (by weight). Suitably, the biocide agents are present inthe cleansing composition in an amount of from about 0.001% (by weight)to about 70.0% (by weight), even more suitably from about 0.001% (byweight) to about 10% (by weight), and even more suitably in an amount offrom about 0.001% (by weight) to about 2.0% (by weight).

When used in combination with the biocide agent in the solution ofcleansing composition, the microencapsulated heat delivery vehicles asdescribed above are suitably present in the cleansing compositions in anamount of from about 0.05% (by weight cleansing composition) to about25% (by weight cleansing composition). More suitably, themicroencapsulated heat delivery vehicles are present in the cleansingcompositions in an amount of from about 1.0% (by weight cleansingcomposition) to about 25% (by weight cleansing composition).

In another embodiment, the cleansing composition is incorporated into asubstrate which can be a woven web, non-woven web, spunbonded fabric,meltblown fabric, knit fabric, wet laid fabric, needle punched web,cellulosic material or web, and combinations thereof, for example, tocreate products such as hand towels, bathroom tissue, dry wipes, wetwipes, and the like. In one preferred embodiment, the cleansingcomposition is incorporated into the wet wipe described above.

Typically, to manufacture the wet wipe with the cleansing composition,the microencapsulated heat delivery vehicle and biocide agent can beembedded inside of the fibrous sheet material or deposited on the outersurface of the fibrous sheet material. In one embodiment, themicroencapsulated heat delivery vehicle and biocide agent are bothembedded inside of the fibrous sheet material. The microencapsulatedheat delivery vehicle can be embedded inside of the fibrous sheetmaterial as described above. Additionally, the biocide agent can beembedded inside of the fibrous sheet material using any method describedabove for embedding the microencapsulated heat delivery vehicle into thecore.

In another embodiment, both the microencapsulated heat delivery vehicleand the biocide agent are deposited on an outer surface of the fibroussheet material. The microencapsulated heat delivery vehicle can bedeposited on one or both outer surfaces of the fibrous sheet material asdescribed above. Typically, the biocide agent can be deposited on anouter surface of the fibrous sheet material using any method describedabove for depositing the microencapsulated heat delivery vehicle on anouter surface of the fibrous sheet material. Similar to themicroencapsulated heat delivery vehicle, when depositing the biocideagent, the biocide agent can be deposited on one outer surface of thefibrous sheet material, or the biocide agent can be applied to bothouter surfaces of the fibrous sheet material.

In yet another embodiment, the microencapsulated heat delivery vehiclecan be embedded into the core of the fibrous sheet material using anymethod described above and the biocide agent can be deposited on one orboth outer surfaces of the fibrous sheet material using any methoddescribed above.

In addition to the methods of application described above, the biocideagents described herein can be applied to the desired area of thefibrous sheet material using the methods of spray coating, slot coatingand printing, and combinations thereof.

In one embodiment, the biocide agents can be microencapsulated in ashell material prior to being introduced into or onto the fibrous sheetmaterial. Generally, the biocide agent can be microencapsulated usingany method known in the art. Suitable microencapsulation shell materialsinclude cellulose-based polymeric materials (e.g., ethyl cellulose),carbohydrate-based materials (e.g., cationic starches and sugars) andmaterials derived therefrom (e.g., dextrins and cyclodextrins) as wellas other materials compatible with human tissues.

The microencapsulation shell thickness may vary depending upon thebiocide agent utilized, and is generally manufactured to allow theencapsulated formulation or component to be covered by a thin layer ofencapsulation material, which may be a monolayer or thicker laminatelayer, or may be a composite layer. The microencapsulation layer shouldbe thick enough to resist cracking or breaking of the shell duringhandling or shipping of the product. The microencapsulation layer shouldalso be constructed such that atmospheric conditions duringmanufacturing, storage, and/or shipment will not cause a breakdown ofthe microencapsulation layer and result in a release of the biocideagent.

Microencapsulated biocide agents applied to the outer surface of thewipes as discussed above should be of a size such that the user cannotfeel the encapsulated shell on the skin during use. Typically, thecapsules have a diameter of no more than about 25 micrometers, anddesirably no more than about 10 micrometers. At these sizes, there is no“gritty” or “scratchy” feeling on the skin when the wipe is utilized.

When used in a product such as a wipe, the microencapsulated heatdelivery vehicles are present in the fibrous sheet material in an amountsuitably of from about 0.33 grams per square meter to about 500 gramsper square meter microencapsulated heat delivery vehicle. More suitably,the wipes comprise from about 6 grams per square meter to about 175grams per square meter microencapsulated heat delivery vehicle, and evenmore suitably, from about 16 grams per square meter to about 75 gramsper square meter microencapsulated heat delivery vehicle.

Suitably, the biocide agent is present in the fibrous sheet material ofthe wet wipe in an amount of suitably 0.01 grams per square meter toabout 50 grams per square meter. More suitably, the biocide agent ispresent in the fibrous sheet material in an amount of from about 0.01grams per square meter to about 25 grams per square meter, and even moresuitably, in an amount of from about 0.01 grams per square meter toabout 0.1 grams per square meter.

The present disclosure is illustrated by the following examples whichare merely for the purpose of illustration and are not to be regarded aslimiting the scope of the disclosure or manner in which it may bepracticed.

EXAMPLE 1

In this example, samples incorporating various size ranges of anhydrouscalcium chloride suspended in mineral oil at 35 wt % were evaluated fortheir ability to generate heat upon introduction into water.

The five size ranges of anhydrous calcium chloride evaluated were: (1)less than 149 microns; (2) 149-355 microns; (3) 710-1190 microns; (4)1190-2000 microns; and (5) 2000-4000 microns. The samples of anhydrouscalcium chloride (Dow Chemical, Midland, Mich.) were dispersed inmineral oil (available as Drakeol 7 LT NF from Penreco, Dickinson,Tex.). The as received anhydrous calcium chloride were screened dryusing a Gilson Sonic Sieve (Gilson Company, Inc. Columbus, Ohio) tocreate two sizes, a 1190-2000 micron size and a 2000-4000 micron size.These powders were then suspended at 35 wt % in mineral oil to form aslurry using a cowles mixing blade. To achieve the smaller sizedistributions, the anhydrous calcium chloride powder required furtherprocessing.

Specifically, the sample of anhydrous calcium chloride having a sizerange of 710-1190 microns was produced by grinding the as receivedanhydrous calcium chloride with a size range of 2000-4000 microns in ahammermill, screening the powder to the desired size, and thensuspending the calcium chloride particles at 35 wt % in mineral oilusing a cowles mixing blade. The sample of anhydrous calcium chloridehaving a size range of 149-355 microns was produced by grinding the asreceived anhydrous calcium chloride with a size range of 2000-4000microns in a hammermill, suspending the calcium chloride particles at 35wt % in mineral oil using a cowles mixing blade and then furtherprocessing this slurry in a Buhler K8 media mill (Buhler, Inc.Switzerland). This media milling process used 0.5 millimeter aluminagrinding media, and rotated at a speed of 1800 revolutions per minute(rpm), for 1.5 hours while slurry was pumped through the millingchamber. While being milled, 0.5 wt % surfactant, available as Antiterra207 (BYK-Chemie, Wesel, Germany) was mixed with the anhydrous calciumchloride to control the viscosity. The sample of anhydrous calciumchloride having a size range of less than 149 microns was produced bygrinding the as received anhydrous calcium chloride with a size range of2000-4000 microns in a hammermill, suspending the calcium chlorideparticles at 35 wt % in mineral oil using a cowles mixing blade and thenfurther processing this slurry in a Buhler K8 media mill (Buhler, Inc.Switzerland). This media milling process used 0.5 millimeter aluminagrinding media, and rotated at a speed of 1800 revolutions per minute(rpm), for 2.5 hours while slurry was pumped through the millingchamber. While being milled, 0.5 wt % surfactant, available as Antiterra207 (BYK-Chemie, Wesel, Germany) was mixed with the anhydrous calciumchloride to control the viscosity.

All five samples were then individually added to 7.0 grams de-ionizedwater and the resulting temperature rise was measured using a BarnantScanning Thermocouple (available from Therm-X of California, Hayward,Calif.). The results are shown in FIG. 3.

As shown in FIG. 3, although all samples delivered an increase in therate of heat release, the sample using anhydrous calcium chloride havinga particle size in the range of 149-355 micrometers generated heat atthe highest rate.

EXAMPLE 2

In this example, samples incorporating various size ranges of anhydrousmagnesium chloride suspended in mineral oil at 35 wt % were evaluatedfor their ability to generate heat upon introduction into water.

The four size ranges of anhydrous magnesium chloride evaluated were: (1)1000-1500 microns; (2) 600-1000 microns; (3) 250-600 microns; and (4)less than 250 microns. To produce the samples of anhydrous magnesiumchloride in mineral oil, the various size ranges of anhydrous magnesiumchloride powder (Magnesium Interface Inc. (Vancouver, B.C., Canada) weresuspended at 35 wt % in mineral oil (available as Drakeol 7 LT NF fromPenreco, Dickinson, Tex.). To produce the samples having anhydrousmagnesium chloride with size ranges of 1000-1500 microns, 600-1000microns, and 250-600 microns, the as received anhydrous magnesiumchloride powder was hand screened into the size ranges desired and thepowders collected. These powders were suspended at 35 wt % in mineraloil using a cowles mixing blade. The sample of anhydrous magnesiumchloride having a size range of less than 250 microns was produced bycoffee grinding (Mr. Coffee Grinder No. 10555, Hamilton Beach) theanhydrous magnesium chloride having a size range of 1000-1500 micronsfor 30 seconds to reduce the size. This sample was then processed usinga Gilson Sonic Sieve (Gilson Company, Inc., Columbus, Ohio) to collectthe particles having a particle size of less than 250 microns. Thispowder was suspend at 35 wt % in mineral oil using a cowles mixingblade.

All four samples were then added to 7.0 grams de-ionized water and theresulting temperature rise was measured using a J type Thermocouple(available from Omega Engineering, Inc., Stamford, Conn.). The resultsare shown in FIG. 4.

As shown in FIG. 4, although all samples delivered an increase in therate of heat release, the sample using anhydrous magnesium chloridehaving a particle size of less than 250 micrometers generated heat atthe highest rate.

EXAMPLE 3

In this Example, six compositions including a heating agent, matrixmaterial, and various surfactants were produced. The viscosities (at 23°C.) of the compositions were measured using a Brookfield Viscometer todetermine which surfactants were preferred for use in the compositionsof the present disclosure.

To produce the compositions, 34.7% (by weight composition) anhydrousmagnesium chloride (available from Magnesium Interface Inc., Vancouver,B.C., Canada), 64.3% (by weight composition) mineral oil (available asDrakeol 7 LT NF from Penreco, Dickinson, Tex.), and 1.0% surfactant (byweight composition) were milled together using a vertical attritor millusing one quarter inch, spherical, ceramic media for a total of 90minutes. The surfactants utilized in the six compositions and theirproperties are shown in Table 1.

TABLE 1 Commercial Ionic Surfactant Source Activity Antiterra 207 BYKChemie Anionic (Wesel, Germany) Disperbyk 166 BYK Chemie Proprietary(Wesel, Germany) Disperbyk 162 BYK Chemie Cationic (Wesel, Germany)BYK-P104 BYK Chemie Anionic (Wesel, Germany) Tergitol TMN-6 UnionCarbide Non-ionic (Houston, HLB = 11.7 Texas) Span 85 Uniqema/ICINon-ionic Surfactants HLB = 1.8 (Malaysia)

The viscosities of the compositions (at 23° C.) were measured using aBrookfield Viscometer having a spindle rotating at 100 revolutions perminute (rpm). The results are shown in Table 2.

TABLE 2 Viscosity at Spindle Number of Surfactant 23° C. (cP) ViscometerAntiterra 207 208 RU3 Disperbyk 166 208 RU3 Disperbyk 162 1366 RU6BYK-P104 306 RU3 Tergitol TMN-6 7120 RU6 Span 85 352 RU3

Samples with the lower viscosities are better suited for use incompositions utilized to make the microencapsulated heat deliveryvehicles of the present disclosure as these compositions are easier towork with and allow for higher loading of heating agents. As such, asshown in Table 2, the compositions made with Antiterra 207 and BYK-P104have the lowest viscosities, and as such, would be preferred surfactantsfor use in some of the compositions of the present disclosure. Moreover,the composition made with Tergitol TMN-6 had the highest viscosity andwould thus be a less preferred surfactant for use in the compositions ofthe present disclosure.

EXAMPLE 4

In this Example a microencapsulated heat delivery vehicle wasmanufactured utilizing calcium chloride as both the encapsulatingactivator and the heating agent.

Calcium chloride (about 20 micrometers in diameter) was introduced intomineral oil (available as Drakeol 7 LT NF from Penreco, Dickinson, Tex.)to form a 25% (by weight) calcium chloride in mineral oil compositionthat was mixed together thoroughly and had a resulting viscosity (25°C.) of about 300 centipoise. This composition was introduced dropwisefrom a separatory funnel into two liters of an Manugel DMB aqueoussodium alginate solution (1% by weight in deionized water, 300centipoise at 25° C., available from ISP Technologies, Inc., Scotland)and allowed to dwell in the solution for about 30 minutes undersufficient stirring to keep the drops formed upon addition into thesodium alginate solution separate. It is also significant to avoidoverstirring, as this can cause high excess calcium release and alginatebroth gelation. Most drops of the composition added were between about 3millimeters in diameter and about 5 millimeters in diameter. After 30minutes dwell time the formed microencapsulated beads were removed fromthe sodium alginate solution and rinsed three times with de-ionizedwater and cast to air-dry overnight at room-temperature. Stablemicroencapsulated heat delivery vehicles were formed.

EXAMPLE 5

In this Example a microencapsulated heat delivery vehicle includingmagnesium oxide was manufactured utilizing calcium chloride as theencapsulating activator.

Calcium chloride (about 20 micrometers in diameter) was introduced into133 grams of propylene glycol and 70 grams of magnesium oxide to form a3% (by weight) calcium chloride composition that was mixed togetherthoroughly and had a resulting viscosity (25° C.) of about 500centipoise. This composition was introduced dropwise from a separatoryfunnel into two liters of an aqueous sodium alginate solution (1% byweight in de-ionized water, 250 centipoise at 25° C.) and allowed todwell in the solution for about 30 minutes under sufficient stirring tokeep the drops formed upon addition into the sodium alginate solutionseparate. It is also significant to avoid overstirring, as this cancause high excess calcium release and alginate broth gelation. Mostdrops of the composition added were between about 3 millimeters indiameter and about 5 millimeters in diameter. After 30 minutes dwelltime the formed microencapsulated beads were removed from the sodiumalginate solution and rinsed three times with de-ionized water and castto air-dry overnight at room-temperature. Stable microencapsulated heatdelivery vehicles were formed.

EXAMPLE 6

In this Example, a microencapsulated heat delivery vehicle includingcalcium chloride as the encapsulating activator was produced.

Calcium chloride (about 20 micrometers in diameter) was introduced intomineral oil (available as Drakeol 7 LT NF from Penreco, Dickinson, Tex.)to form a 25% (by weight) calcium chloride composition that was mixedtogether thoroughly and had a resulting viscosity (25° C.) of about 300centipoise. This composition was introduced dropwise from a separatoryfunnel into one half liter of an anionic water dispersedbutadiene/acrylonitrile latex emulsion (100 grams of Eliochem ChemigumLatex 550 (commercially available from Eliochem, France) dissolved in500 grams of de-ionized water) and allowed to dwell in the solution forabout 10 minutes under sufficient stirring to keep the drops formed uponaddition into the latex emulsion solution separate. Most drops of thecomposition added were between about 3 millimeters in diameter and about5 millimeters in diameter. During a 30-minute dwell time, themicroencapsulated beads were formed in a latex shell. These beads wereremoved from the latex emulsion and rinsed three times with de-ionizedwater and cast to air-dry overnight at room-temperature. Stablemicroencapsulated vehicles were formed.

EXAMPLE 7

In this Example a microencapsulated heat delivery vehicle including afragrance oil was manufactured utilizing calcium chloride as theencapsulating activator.

A mixture (1 gram) of 25% (by weight) calcium chloride and 75% (byweight) mineral oil (available as Drakeol 7 LT NF from Penreco,Dickinson, Tex.) was added to 9 grams of Red Apple Fragrance Oil(commercially available from Intercontinental Fragrances, Houston, Tex.)and the resulting composition thoroughly mixed. The resultingcomposition was added dropwise from a separatory funnel to a 1% (byweight) sodium alginate in de-ionized water solution and allowed todwell in the solution for about 20 minutes under sufficient stirring tokeep the drops formed upon addition to the sodium alginate solutionseparate. It is also significant to avoid overstirring, as this cancause high excess calcium release and alginate broth gelation. After the20 minute dwell time, the formed microencapsulated beads were removedfrom the sodium alginate solution and rinsed three times with de-ionizedwater and cast to air-dry overnight at room-temperature. Stablemicroencapsulated vehicles were formed.

EXAMPLE 8

In this Example, a microencapsulated heat delivery vehicle including aheating agent surrounded by a hydrophobic wax material was producedusing a method of the present disclosure. This microencapsulated heatdelivery vehicle was then analyzed to determine its ability to generateheat after being contacted with water as compared to a control sample,which was a microencapsulated heat delivery vehicle including a heatingagent not surrounded by a hydrophobic wax material.

To produce the heating agent surrounded by a hydrophobic wax materialfor inclusion in the microencapsulated heat delivery vehicle, 100 gramsof a hydrophobic wax material, available as Polywax 500 fromFischer-Tropsch Wax Products (Sugar Land, Tex.) was melted in a steelbeaker at a temperature of about 110° C. and thoroughly mixed with 200grams anhydrous magnesium chloride salt grains (available from MagnesiumInterface Inc., Vancouver, B.C., Canada) having a particle size of about100 micrometers. The agglomerated mass was allowed to cool to roomtemperature. A coffee grinder (commercially available as Mr. Coffee®Grinder from Hamilton Beach) was then used to break the mass intoparticles having a particle size of approximately 3 micrometers to 5micrometers in diameter. A portion of these particles was introducedinto water and found not to be soluble. This indicated the presence of acontinuous wax coating surrounding the magnesium chloride.

Thirty grams of wax-coated magnesium chloride was added to a 30-gramsuspension of 10% (by weight) calcium chloride/25% (by weight) magnesiumchloride/65% (by weight) mineral oil to make a paste. The paste wasadded slowly to 2 liters of a 0.5% (by weight) aqueous sodium alginatesolution. Using an overhead stirrer rotating at 700 revolutions perminute (rpm), the paste was broken down into emulsion forming beadshaving a diameter of about 2 millimeters. The beads were allowed todwell for approximately 10 minutes in the high shear aqueous environmentto form a crosslinked alginate shell. After 10 minutes, the beads wereremoved and rinsed with de-ionized water.

Three grams of the microencapsulated heat delivery vehicles were crushedin the presence of 7.0 grams water to determine the ability of themicroencapsulated heat delivery vehicles to generate heat. Thetemperature of the water increased by approximately 10° C.

A control sample was then produced and compared to the microencapsulatedheat delivery vehicles produced above. To produce the control sample, a5% (by weight) calcium chloride/25% (by weight) magnesium chloride/70%(by weight) mineral oil paste was produced as described above with theexception that there was not any wax coated magnesium chloride. Theresulting beads were then crushed in the presence of 7.0 grams water.With the control sample, a temperature increase of approximately 5° C.was detected.

The results show that the heat of hydration and heat of solution of theanhydrous magnesium chloride of the microencapsulated heat deliveryvehicle including a heating agent surrounded by a hydrophobic waxmaterial was maintained, while the magnesium chloride of the controlsample was deactivated either during the high shearemulsion/encapsulation processes or in the rinsing and drying of thebeads.

EXAMPLE 9

In this Example, a microencapsulated heat delivery vehicle including aheating agent surrounded by a hydrophobic wax material was produced.This microencapsulated heat delivery vehicle was analyzed to determineits ability to generate heat upon contact with water.

To produce the heating agent surrounded by a hydrophobic wax material, ablend of 95% (by weight) anhydrous magnesium chloride (available fromMagnesium Interface Inc., Vancouver, B.C., Canada) and 5% (by weight)Polywax 500 (available from Fischer-Tropsch Wax Products, Sugar Land,Texas) was prepared by heating 500 grams of the blend to a temperatureof 110° C. in a closed container. The blend was periodically stirredover a 2-hour period. While still hot, 4-millimeter ceramic millingmedia (Dynamic Ceramic, United Kingdom) were added to the container androlled on a jar mill until the blend cooled to room temperature.

Fifty grams of the 95% (by weight) anhydrous magnesium chloride/5% (byweight) wax blend was added to 50 grams of a composition comprising 10%(by weight) calcium chloride and 90% (by weight) mineral oil. Theresulting paste was added slowly into 2 liters of a 0.5% (by weight)aqueous sodium alginate solution. Using an overhead stirrer rotating at650 rpm, the paste was broken down into emulsion forming beads having adiameter of between about 2 to 4 millimeters. The beads were allowed todwell for approximately 10 minutes in the high shear aqueous environmentto form a crosslinked alginate shell. After 10 minutes the beads wereremoved and rinsed with water.

Three grams of the microencapsulated heat delivery vehicle were crushedin the presence of 7.0 grams water to determine the ability of themicroencapsulated heat delivery vehicle to generate heat. Thetemperature of the water increased by approximately 18° C. indicatingthat the wax coating protected the heating agent during the aqueouscrosslinking process.

EXAMPLE 10

In this Example, spherical core materials containing a water solublematerial were encapsulated with a moisture protective layer. Thesesamples were then added to low conductivity water and the conductivityof this solution was monitored over time to compare the behavior ofmoisture protected and unprotected particles.

To produce the spherical core material including a moisture protectivelayer, 7.0 grams of approximately 2-millimeter sized beads containing 80wt % wax (available as Dritex C from Dritex International Limited,Essex, United Kingdom) and 20 wt % sodium sulfate (a water solublematerial) were formed in the following manner. Dritex C wax and sodiumsulfate were melted to 100° C. in a pressure pot. A standard prillingprocess was used to form the beads wherein the melted composition wassprayed out of a single nozzle fluid and the 2 millimeter beads werecollected. To form the moisture protective layer, 7 grams of these beadswere introduced into a glass beaker. Using a dropper, 0.295 grams ofPluracol GP-430, which is a polyol, available from BASF Corporation(Wyandotte, Mich.), was added to the glass beaker. The mixture was handstirred using a spatula for about 5 minutes to fully coat the corematerial. After stirring the mixture, 0.314 grams Lupranate M20-S, whichis a polyether polyol available from BASF Corporation (Wyandotte,Mich.), was added to the mixture using a dropper. The mixture, includingthe Lupranate, was hand stirred using a spatula for about 15 minutes.The mixture was then allowed to oven cure at 60° C. for 15 minutes toform the moisture protective layer on the spherical core material.

2.0 grams of core material particles were added to 120 grams ofdeionized water in a 150 milliliter beaker. The conductivity of thedeionized water was then measured as a function of time using an Orionmodel 135 Waterproof Conductivity/TDS/Salinity/Temperature Meter(Fischer Scientific). The conductivity of the control sample (sphericalcore material without any moisture protective coating was also analyzed.The results are shown in FIG. 5.

As shown in FIG. 5, the core material particles with a protective layerhave a slower rate of conductivity increase over non protectedmaterials. It is advantageous to have a low release of water sensitivematerials to insure moisture protection of the core material.

EXAMPLE 11

In this Example, anhydrous calcium chloride particles were treated toimpart a moisture protective layer thereon. The ability of the calciumchloride particles including the moisture protective layer to generateheat after contact with water was analyzed and compared to a controlsample, which included calcium chloride particles without a moistureprotective layer.

To impart the moisture protective layer onto the calcium chlorideparticles, 250 grams anhydrous calcium chloride with a particle size ofabout 2 millimeters (available from The Dow Chemical Company, Midland,Mich.) were added to a V-blender, rotating at a speed of 62 revolutionsper minute (rpm) and maintained at a temperature of 60° C. Rotation ofthe V-blender was stopped and a dropper was used to add 2.50 grams ofPluracol GP 430, a polyol available from BASF Corporation (Wyandotte,Mich.) to form a mixture of anhydrous calcium chloride and Pluracol GP430. The mixture was blended in the V-blender for approximately oneminute. The V-blender was again stopped and 2.50 grams Lupranate M20-S,a polyether polyol available from BASF Corporation (Wyandotte, Mich.),was added. The mixture was blended for about 10 minutes. After blendingthe mixture, about 2.50 grams of refined yellow #1 Carnauba wax,available from Sigma-Aldrich Co. (St. Louis, Mo.) was added and theblender again started. The temperature of the mixture in the blender wasincreased to 95° C. The blending was continued for about 15 minutes at95° C. The blending was stopped and the mixture was allowed to cool toambient temperature.

A second addition of Pluracol GP 430, Lupranate M20-S, and yellow #1Carnauba wax was added to the blended mixture in the same manner asdescribed above. Additionally, a third addition of Pluracol GP 430 andLupranate was added and blended as described above. After blending themixture, the mixture was allowed to oven cure at 60° C. for 15 minutes.The mixture was allowed to cool and sealed in a jar. After 24 hours, theyellow #1 Carnauba wax was added to the cooled mixture in the mannerdescribed above and the mixture was again allowed to cool to form themicroencapsulated heat delivery vehicle including a moisture protectivelayer.

Four samples of the calcium chloride particles including a moistureprotective layer were then analyzed for their ability to generate heatafter exposure to water. A control sample (calcium chloride) was alsotested for heat generating capabilities and compared to the four samplesof calcium chloride having a moisture protective layer.

To analyze the samples for heat generation, 0.80 grams of each sample ofcalcium chloride including a moisture protective layer was added to fourseparate vials each containing 7.0 grams of de-ionized water and 0.73grams of the control sample was added to a fifth vial containing 7.0grams of de-ionized water. Using a J type thermocouple (commerciallyavailable from Omega Engineering, Inc., Stamford, Conn.) and a datalogger, the temperature of the samples was measured over a period of 180seconds. The four vials containing the samples of microencapsulated heatdelivery vehicle including a moisture protective layer were allowed toremain in the de-ionized water for 0.5 hours, 1.0 hour, 1.5 hours, and2.0 hours, respectively, at which time the samples were activated bycrushing the samples by hand using a metal rod. The temperature of thewater in the four vials was measured for a period of 180 seconds aftercrushing the samples. The results are shown in FIG. 6.

As shown in FIG. 6, the samples of microencapsulated heat deliveryvehicles including a moisture protective layer continued to produce heatafter soaking in de-ionized water after two hours. The control samplehaving no protective layer, however, produced heat immediately uponbeing introduced into water but only for a short period of time.

EXAMPLE 12

In this Example, microencapsulated heat delivery vehicles including amoisture protective layer comprising various amounts of a mixture ofSaran F-310 and polymethylmethacrylate were produced. The samples werethen evaluated for water barrier properties by soaking the samples in awetting solution at a temperature of approximately 50° C., and thensubmitting the samples to a heat test.

Three levels of moisture protective layer on the microencapsulated heatdelivery vehicles were evaluated: (1) 17% (by weight microencapsulatedheat delivery vehicle); (2) 23% (by weight microencapsulated heatdelivery vehicle; and (3) 33% (by weight microencapsulated heat deliveryvehicle). To produce the Saran F-310/polymethylmethacrylate solution forapplication to the microencapsulated heat delivery vehicles to form themoisture protective layer, 80 grams Saran F-310, available from DowChemical Company (Midland, Mich.) was dissolved in a 320-gram solutionof 70% (by weight) methyl ethyl ketone (MEK) and 30% (by weight)toluene, and 20 grams polymethylmethacrylate was dissolved in 180 gramsacetone. The Saran F-310 and polymethylmethacrylate solutions were thenblended together to produce a solution comprising 20% (by weight) solidswherein 90% (by weight solids) was Saran F-310 and 10% (by weightsolids) was polymethylmethacrylate (treatment solution).

Once the treatment solution was produced, the microencapsulated heatdelivery vehicles including the desired amounts of moisture protectivelayer were produced. First, in order to provide a continuous layer ofshell material at the “base” or bottom of the microencapsulated heatdelivery vehicles, a glass syringe was used to apply 1.5 grams of thetreatment solution to a sheet of Saran film, which had been stretchedover a flat surface (17″×22″ metal sheet). The treatment solution wasallowed to dry until it reached the tacky stage. The Saran film surfacewas marked with circles of approximately three inches in diameter inorder to be used as a guide and to facilitate even coating of the shellmaterial. For the 17% (by weight) coating, three grams ofmicroencapsulated heat delivery vehicles as produced in Example 8 werethen placed in an aluminum weigh pan and blended with 1.5 grams of thetreatment solution until the beads were well coated. Using a scoopula,the beads were stirred in the solution until well coated. The coatedbeads were then poured with the remaining treatment solution onto thebase coat layer on the Saran film and allowed to dry completely.

The samples including 23% (by weight) moisture protective layer wereproduced using the method described above with the exception of using2.25 grams of the treatment solution instead of 1.5 grams of treatmentsolution.

To produce the samples including 33% (by weight) shell material, twobase coats were produced using the method described above, eachcomprising 1.9 grams of treatment solution. The first base coat wasallowed to dry prior to applying the second base coat. Three grams ofthe alginate beads were blended with 1.9 grams of treatment solution inthe aluminum weigh pan. The coated microencapsulated heat deliveryvehicles were then poured onto the base coat layers and allowed to dryto the tacky stage. An additional 1.9 grams of treatment solution wasapplied over the coated alginate beads and allowed to completely dry.

Sixteen samples of each coating amount were then analyzed for theirability to generate heat after being immersed in the wetting solutionand held at a temperature of 50° C. for various lengths of time rangingfrom 0 to 14 days. To analyze the samples, 3.0 grams of each sample areadded to an empty balloon. A wetting solution (7 grams) comprising: 98%(by weight) water, 0.6% (by weight) potassium laureth phosphate, 0.3%(by weight) glycerin, 0.3% (by weight) polysorbate 20, 0.2% (by weight)tetrasodium EDTA, 0.2% (by weight) DMDM hydrantoin, 0.15% (by weight)methylparaben, 0.07% (by weight) malic acid, 0.001% (by weight) aloebarbadensis, and 0.001% (by weight) tocopheryl acetate. A thermocoupleis then introduced into the balloon to monitor the temperature. Thesample beads were then activated by hand crushing the beads and thetemperature increase is measured. The results for each coating amountwere averaged and shown in FIG. 7.

EXAMPLE 13

In this Example, samples of microencapsulated heat delivery vehiclesincluding non-polymeric moisture protective layers were produced usingelectroless silver plating on microencapsulated heat delivery vehicles.The samples were then analyzed for their ability to generate heat.

To produce the electroless silver coating solutions, a sensitizersolution, reducer solution, and silver coating solution were produced.The sensitizer solution was produced by adding 4.8 grams of 22° BaumeHCl (Fischer Scientific Technical Grade) to 946 milliliters ofde-ionized water. 10 grams of 98% (by weight) stannous chloride,available from Sigma-Aldrich Co. (St. Louis, Mo.) was then added to thesolution. To produce the reducer solution, 170 grams dextrose wasdissolved in 946 milliliters de-ionized water. To produce the silvercoating solution, 10 grams potassium hydroxide was dissolved in 3 litersof de-ionized water. Once dissolved, 50 milliliters of ammoniumhydroxide was added to the solution and then finally, 25 grams of silvernitrate was added during vigorous agitation using a 3 blade-2 stirrermixer, mixing at about 2000 revolutions per minute (rpm). The agitationwas continued until the brown precipitate was re-dissolved. De-ionizedwater was added to the mixture in an amount to produce one gallon ofsilver coating solution.

Prior to coating the microencapsulated heat delivery vehicles asdescribed below, the vehicles were analyzed to determine their abilityto generate heat as measured in Example 12 above.

Fifteen grams of microencapsulated heat delivery vehicles as made inExample 8 were placed into a quart jar, which was then filledthree-quarters full with sensitizer solution. The jar was then agitatedby turning the jar end-to-end for about 10 minutes. The beads were thenagitated by stirring by hand for about 10 minutes and rinsed thoroughlywith water. The beads were then transferred to a quart jar filledthree-quarters full with silver coating solution. To the quart jar, 24milliliters of reducer solution was added and the jar was capped andturned end-to-end for approximately 5 minutes. The solution was thenpoured through a screen to strain the beads and the beads were washed 3to 5 times thoroughly with de-ionized water. This electroless silverplating process was repeated three more times to produce a four-layersilver coating on the alginate beads.

Three grams of coated microencapsulated heat delivery vehicles wereanalyzed for their ability to generate heat after being immersed in thewetting solution of Example 12 and held at 50° C. The beads were testedat intervals of 4 hours, 8 hours, 24 hours, and 48 hours. The resultsare shown in FIG. 8.

As shown in FIG. 8, while the electroless silver plating process doesproduce a microencapsulated heat delivery vehicle including a moistureprotective layer, the plating process greatly diminishes the heatgenerating ability of the alginate beads.

EXAMPLE 14

In this Example, samples of pan coated alginate microencapsulated heatdelivery vehicles having three different coating thicknesses wereproduced and analyzed for particle strength. Specifically, the sampleswere analyzed to determine the rupture point or the point at which therupture force is strong enough to rupture the particles.

Four samples of P7-A pan coated alginate microencapsulated heat deliveryvehicle were produced by using the method of Example 12. Two samples ofP7-B pan coated alginate microencapsulated heat delivery vehicle wereproduced using the same method as used to produce the P7-A samples withthe exception that 1.5 times the amount of coating was used to coat themicroencapsulated heat delivery vehicle. Three samples of P7-C pancoated alginate microencapsulated heat delivery vehicle were producedusing the same method as used to produce the P7-A samples with theexception that 2.5 times the amount of coating was used to coat themicroencapsulated heat delivery vehicle.

To test particle strength, a TA Texture Analyzer (Software Version 1.22)(available from Texture Technologies Corporation, Scarsdale, N.Y.) wasused. Specifically, a single particle of each sample was independentlyplaced on a polycarbonate plate and force measurements were made using aone-quarter inch to one inch diameter flat probe, moving at a rate ofabout 0.25 millimeter/second to about 5.0 millimeters/second. As theforce load was applied by the probe, the particle deformed until itcracked or collapsed. Generally, the deformation of the particlecontinues until the applied force increases exponentially, indicatingthat the shell of the particle has been ruptured. As used herein, the“rupture point” is defined as the height of the first peak on the graphsin FIGS. 9-11, indicating a decrease in resistance caused by the outershell breaking. The results of the measurements are shown in Table 3 andFIGS. 9-11.

TABLE 3 Pan Coated Alginate Force (grams) Microencapsulated required toHeat Delivery rupture sample Vehicle Sample Sample No. particle P7-A 1284 2 283 3 71 4 264 P7-B 1 228 2 151 P7-C 1 526 2 297 3 323

As shown in Table 3 and FIGS. 9-11, more force was required to crushsamples of P7-C than samples of P7-A or P7-B. Additionally, as shown inFIGS. 9-11, samples of P7-C, did not appear to deform as samples of P7-Aor P7-B, as indicated by the steeper slope of the force curve.

EXAMPLE 15

In this Examples, samples of alginate coated micorencapsulated heatdelivery vehicle were produced and analyzed for particle strength.Specifically, the samples were analyzed to determine the rupture pointor the point at which the rupture force is strong enough to rupture theparticles.

Six samples of P7-F alginate coated microencapsulated heat deliveryvehicle were produced using the method of Example 12. Seven samples ofP7-G alginate coated microencapsulated heat delivery vehicle wereproduced using the same method as for making the samples of P7-F withthe exception that the samples of P7-G were soaked in the wettingsolution of Example 12 for 48 hours at a temperature of 50° C. Foursamples of P7-J alginate coated microencapsulated heat delivery vehiclewere produced using the method of Example 8. The P7-J samples were thencoated with Saran F310 using the method of Example 12 above.

To test particle strength, a TA Texture Analyzer (available fromTextureTechnologies, Scarsdale, N.Y.) was used as describe above. The resultsof the measurements are shown in Table 4 and FIGS. 12-14.

TABLE 4 Pan Coated Alginate Force (grams) Microencapsulated required toHeat Delivery rupture sample Vehicle Sample Sample No. particle P7-F 1212 2 64 3 190 4 113 5 44 6 145 P7-G 1 163 2 49 3 76 4 260 5 44 6 32P7-J 1 88 2 233 3 84 4 49

As shown in Table 4 and FIGS. 12-14, more force was required to crushsamples of P7-F than samples of P7-G or P7-J. Additionally, as shown inFIG. 13, after the outer shell of the P7-G samples ruptured, thecompression force drops to almost zero, which suggests that the P7-Gparticles are hollow and offer no resistance after the outer shell isruptured. These results are compared to the P7-F samples, which were notsoaked in wetting solution. Once the outer shell ruptured, thecompression force drops on the P7-F samples, but plateaus above zero.This resistance after the outer shell of the P7-F samples rupture isattributed to the resistance of the anhydrous magnesium chloride oilmixture being forced out of the shell.

EXAMPLE 16

In this Example, samples of alginate coated microencapsulated heatdelivery vehicle comprising either silica or chitosan were produced andanalyzed for particle strength. Specifically, the samples were analyzedto determine the rupture point or the point at which the rupture forceis strong enough to rupture the particles.

Three samples of P6-C alginate coated microencapsulated heat deliveryvehicle were produced using the method of Example 12. Five samples ofP6-D alginate coated microencapsulated heat delivery vehicle wereproduced using the same method as for making the samples of P6-C withthe exception that the samples of P6-D were additionally coated with a0.5% (by weight) aqueous solution of chitosan prior to drying the beadsto provide improved particle strength. The samples of P6-D were thenrinsed and allowed to air-dry. Three samples of P6-E alginate coatedmicroencapsulated heat delivery vehicle were produced using the samemethod as for making the samples of P6-C with the exception that thesamples of P6-E were additionally coated with fumed silica after dryingthe beads to provide improved particle strength. The samples of P6-Ewere coated with 5% (by weight) Cabot M5 silica and allowed to air-dryand then jar rolled for approximately 2 hours.

To test particle strength, a TA Texture Analyzer (available from TextureTechnologies, Scarsdale, N.Y.) was used as described above. The resultsof the measurements are shown in Table 5 and FIGS. 15-17.

TABLE 5 Pan Coated Alginate Force (grams) Microencapsulated required toHeat Delivery rupture sample Vehicle Sample Sample No. particle P6-C 138 2 31 3 56 P6-D 1 164 2 84 3 123 4 74 5 59 P6-E 1 71 2 54 3 72

As shown in Table 5 and FIGS. 15-17, more force was required to crushsamples of P6-D and P6-E than samples of P6-C. As such, it appears thatby adding the additional chitosan or silica protective layers theparticle strengths of the samples are increased.

EXAMPLE 17

In this Example, a microencapsulated heat delivery vehicle including afugitive layer was produced.

To produce the microencapsulated heat delivery vehicle, calcium chloride(about 20 micrometers in particle size) was introduced into mineral oilto form a 25% (by weight) calcium chloride/75% (by weight) mineral oilcomposition that was mixed together thoroughly and had a resultingviscosity (25° C.) of about 300 centipoise. This composition wasintroduced dropwise from a separatory funnel into two liters of a sodiumalginate solution (1% by weight in de-ionized water, 300 centipoise at25° C.) and allowed to dwell in the solution for about 30 minutes undersufficient stirring to keep the drops formed upon addition into thesodium alginate solution separate. Most drops of the composition addedwere between about 4 millimeters in diameter and about 6 millimeters indiameter. After 30 minutes dwell time the formed microencapsulated beadswere removed from the sodium alginate solution and rinsed three timeswith de-ionized water and cast to air-dry at room temperature overnight.Stable microencapsulated heat delivery vehicles were formed having adiameter of about 4 to about 6 millimeters.

Once the microencapsulated heat delivery vehicles were formed, themicroencapsulated heat delivery vehicles were surrounded by a moistureprotective layer. To produce the moisture protective layer forsurrounding the microencapsulated heat delivery vehicles, themicroencapsulated heat delivery vehicles were placed onto a Tefloncoated pan and individually coated with a 30% (by weight) Saran F-310 inmethyl ethyl ketone (MEK) solution using a pipette. The MEK was allowedto evaporate leaving the saran film as a moisture protective layersurrounding the microencapsulated heat delivery vehicles to formsubstantially fluid impervious microencapsulated heat delivery vehicles.

A polyvinyl alcohol solution was then used to produce a fugitive layerto surround the substantially fluid impervious microencapsulated heatdelivery vehicles. To produce the fugitive layer, a 20% (by weight)solution of polyvinyl alcohol was prepared by hand stirring 20 grams of87-89% hydrolyzed polyvinyl alcohol (available from Sigma-Aldrich Co.,St. Louis, Mo.) into 80 grams of de-ionized water having a temperatureof 70° C. The polyvinyl alcohol solution was then applied using apipette to the substantially fluid impervious microencapsulated heatdelivery vehicles. Two coats of the polyvinyl solution were applied tothe substantially fluid impervious microencapsulated heat deliveryvehicles. The substantially fluid impervious microencapsulated heatdelivery vehicles coated with the polyvinyl alcohol solution were thendried in an oven at a temperature of 50° C. for 1 hour to produce themicroencapsulated heat delivery vehicles including the fugitive layer.

EXAMPLE 18

In this example, a microencapsulated heat delivery vehicle including afugitive layer was produced.

Substantially fluid impervious microencapsulated heat delivery vehicleswere produced as in Example 17 above. A Ticacel® HV solution was thenused to produce a fugitive layer to surround the substantially fluidimpervious microencapsulated heat delivery vehicles. To produce thefugitive layer, a 1% (by weight) solution of Ticacel® HV was prepared byhand stirring 1 gram of Ticacel® HV powder (commercially available fromTIC Gum, Belcamp, Md.) into 99 grams of de-ionized water at roomtemperature. The Ticacel® HV solution was then applied using a pipetteto the substantially fluid impervious microencapsulated heat deliveryvehicles. Two coats of the Ticacel® HV solution were applied to thesubstantially fluid impervious microencapsulated heat delivery vehicles.The substantially fluid impervious microencapsulated heat deliveryvehicles coated with the Ticacel® HV solution were then dried in an ovenat a temperature of 50° C. for 1 hour to produce the microencapsulatedheat delivery vehicles including the fugitive layer.

EXAMPLE 19

In this example, a microencapsulated heat delivery vehicle including afugitive layer was produced.

Substantially fluid impervious microencapsulated heat delivery vehicleswere produced as in Example 17 above. A gum solution was then used toproduce a fugitive layer to surround the substantially fluid imperviousmicroencapsulated heat delivery vehicles. To produce the fugitive layer,a 10% (by weight) solution of Gum Arabic FT was prepared by handstirring 10 grams of Gum Arabic FT (commercially available from TIC Gum,Belcamp, Md.) into 90 grams of de-ionized water at room temperature. TheGum Arabic FT solution was then applied using a pipette to thesubstantially fluid impervious microencapsulated heat delivery vehicles.To half of the substantially fluid impervious microencapsulated heatdelivery vehicles, two coats of the Gum Arabic FT solution were applied.To the other half of the substantially fluid imperviousmicroencapsulated heat delivery vehicles, four coats of the Gum ArabicFT solution were applied. The substantially fluid imperviousmicroencapsulated heat delivery vehicles coated with the Gum Arabic FTsolution were then dried in an oven at a temperature of 50° C. for 1hour to produce the microencapsulated heat delivery vehicles includingthe fugitive layer.

EXAMPLE 20

In this example, a microencapsulated heat delivery vehicle including afugitive layer was produced.

Substantially fluid impervious microencapsulated heat delivery vehicleswere produced as in Example 17 above. A starch solution was then used toproduce a fugitive layer to surround the substantially fluid imperviousmicroencapsulated heat delivery vehicles. To produce the fugitive layer,a 30% (by weight) solution of PURE-COTE® B-792 starch was prepared byhand stirring 30 grams of PURE-COTE® B-792 starch (commerciallyavailable from Grain Processing Corporation, Muscatine, Iowa,) into 70grams of de-ionized water having a temperature of 70° C. The B-792starch solution was then applied using a pipette to the substantiallyfluid impervious microencapsulated heat delivery vehicles. Two coats ofthe B-792 starch solution were applied to the substantially fluidimpervious microencapsulated heat delivery vehicles. The substantiallyfluid impervious microencapsulated heat delivery vehicles coated withthe B-792 starch solution were then dried in an oven at a temperature of50° C. for 1 hour to produce the microencapsulated heat deliveryvehicles including the fugitive layer.

EXAMPLE 21

In this Example, the Gum Arabic FT fugitive shell made in Example 19 isremoved from the substantially fluid impervious microencapsulated heatdelivery vehicle.

To remove the fugitive shell, the substantially fluid imperviousmicroencapsulated heat delivery vehicles including the fugitive shellwere immersed in room temperature de-ionized water for 30 minutes. Thefugitive shell appeared to dissolve in the water and the substantiallyfluid impervious microencapsulated heat delivery vehicle became visiblysofter.

EXAMPLE 22

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate a strawberry fragrance oil.

To produce the encapsulated strawberry fragrance oil, strawberryfragrance oil (commercially available from Intercontinental Fragrances,Houston, Tex.) was utilized to produce a milled (24 hours with onequarter inch zirconium grinding media) 10% (by weight) calciumchloride/89% (by weight) mineral oil (available from Penreco, Dickinson,Tex.)/1% (by weight) strawberry fragrance oil blend in a 250-gram jar toform a dispersion. Essentially all of the dispersion was then addeddropwise to 200 grams of a 0.5% (by weight) aqueous sodium alginatesolution including 0.05% (by weight) sodium lauryl sulfate in ahalf-liter beaker. Specifically, the drops were added to the shoulder ofa one inch diameter vortex and allowed to dwell for about 20 minutesbefore being removed. The resulting encapsulated beads were cast onto ascreen and rinsed twice with de-ionized water to wash away any unreactedalginate solution. The encapsulated beads were dried at 60° C. for 24hours. The dried encapsulated beads were stable and had a diameter ofless than 10,000 micrometers.

EXAMPLE 23

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate an alcohol.

Ethanol was utilized to produce a milled (24 hours with one quarter inchzirconium grinding media) 10% (by weight) calcium chloride/89% (byweight) mineral oil (available from Penreco, Dickinson, Tex.)/1% (byweight) ethanol blend in a 250-gram jar to form a dispersion.Essentially all of the dispersion was then added dropwise to 200 gramsof a 0.5% (by weight) aqueous sodium alginate solution including 0.05%(by weight) sodium lauryl sulfate in a half-liter beaker. Specifically,the drops were added to the shoulder of a one inch diameter vortex andallowed to dwell for about 20 minutes before being removed. Theresulting encapsulated beads were cast onto a screen and rinsed twicewith de-ionized water to wash away any unreacted alginate solution. Theencapsulated beads were dried at 60° C. for 24 hours. The driedencapsulated beads were stable and had a diameter of less than 10,000micrometers.

EXAMPLE 24

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate a vegetable oil.

To produce the encapsulated vegetable oil, pure soybean vegetable oil(commercially available as Roundy's vegetable oil from Roundy's,Milwaukee, Wis.) was utilized to produce a milled (1.5 hours with onequarter inch zirconium grinding media) 10% (by weight) calciumchloride/90% (by weight) vegetable oil blend in an attritor mill to forma dispersion. The dispersion (100 grams) was then added dropwise to 2000grams of a 0.5% (by weight) aqueous sodium alginate solution including0.05% (by weight) sodium lauryl sulfate in a half-liter beaker.Specifically, the drops were added to the shoulder of a one inchdiameter vortex and allowed to dwell for about 20 minutes before beingremoved. The resulting encapsulated beads were cast onto a screen andrinsed twice with de-ionized water to wash away any unreacted alginatesolution. The encapsulated beads were dried at 60° C. for 24 hours. Thedried encapsulated beads were stable and had a diameter size of lessthan 10,000 micrometers.

EXAMPLE 25

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate yeast.

To produce the encapsulated yeast, 9 grams yeast (commercially availableas Red Star® active dry yeast, Milwaukee, Wis.) was added to a 1-grammilled (24 hours with one quarter inch zirconium grinding media) 10% (byweight) calcium chloride/90% (by weight) mineral oil (available fromPenreco, Dickinson, Tex.) blend in an attritor mill to form adispersion. Essentially all of the dispersion was then added dropwise to2000 grams of a 0.5% (by weight) aqueous sodium alginate solutionincluding 0.05% (by weight) sodium lauryl sulfate in a half-literbeaker. Specifically, the drops were added to the shoulder of a one inchdiameter vortex and allowed to dwell for about 20 minutes before beingremoved. The resulting encapsulated beads were cast onto a screen andrinsed twice with de-ionized water to wash away any unreacted alginatesolution. The encapsulated beads were dried at 60° C. for 24 hours. Thedried encapsulated beads were stable and had a diameter of less than10,000 micrometers.

EXAMPLE 26

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate three different antioxidants.

The three types of antioxidants that were encapsulated included: Ethanox330 (available from Albemale Corporation, Baton Rouge, La.), gallicacid, and methyl gallate. To encapsulate Ethanox 330, Ethanox 330 wasutilized to produce a milled (24 hours with one quarter inch zirconiumgrinding media) 10% (by weight) calcium chloride/89% (by weight) mineraloil (available from Penreco, Dickinson, Tex.)/1% (by weight) Ethanox 330blend in a 250-gram jar to form a dispersion. Essentially all of thedispersion was then added dropwise to 200 grams of a 0.5% (by weight)sodium alginate solution including 0.05% (by weight) sodium laurylsulfate in a half-liter beaker. Specifically, the drops were added tothe shoulder of a one inch diameter vortex and allowed to dwell forabout 20 minutes before being removed. The resulting encapsulated beadsare cast onto a screen to be rinsed twice with de-ionized water to washaway any unreacted alginate solution. The encapsulated beads are driedat 60° C. for 24 hours. The dried encapsulated beads were stable and hada diameter of less than 10,000 micrometers.

To encapsulate gallic acid and methyl gallate, the method describedabove for encapsulating Ethanox 330 was repeated for each antioxidantwith the exception of replacing Ethanox 330 with either gallic acid ormethyl gallate. Similar to the encapsulated Ethanox 330 above, theencapsulated beads containing either gallic acid or methyl gallate werestable and had a diameter of less than 10,000 micrometers.

EXAMPLE 27

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate a vitamin.

Vitamin C (commercially available from Sigma-Aldrich Co., St. Louis,Mo.) was utilized to produce a milled (24 hours with one quarter inchzirconium grinding media) 10% (by weight) calcium chloride/89% (byweight) mineral oil (available from Penreco, Dickinson, Tex.)/1% (byweight) vitamin C blend in a 250-gram jar to form a dispersion.Essentially all of the dispersion was then added dropwise to 200 gramsof a 0.5% (by weight) sodium alginate solution including 0.05% (byweight) sodium lauryl sulfate in a half-liter beaker. Specifically, thedrops were added to the shoulder of a one inch diameter vortex andallowed to dwell for about 20 minutes before being removed. Theresulting encapsulated beads are cast onto a screen to be rinsed twicewith de-ionized water to wash away any unreacted alginate solution. Theencapsulated beads are dried at 60° C. for 24 hours. The driedencapsulated beads had a diameter of less than 10,000 micrometers.

EXAMPLE 28

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate a coloring agent.

The coloring agent encapsulated was oil soluble LCW D&C yellow 11(available from Hilton Davis Chemical Company, Cincinnati, Ohio). Toencapsulate LCW D&C yellow 11, LCW D&C yellow 11 was utilized to producea milled (24 hours with one quarter inch zirconium grinding media) 10%(by weight) calcium chloride/89% (by weight) mineral oil (available fromPenreco, Dickinson, Tex.)/1% (by weight) LCW D&C yellow 11 blend in a250-gram jar to form a dispersion. Essentially all of the dispersion wasthen added dropwise to 200 grams of a 0.5% (by weight) sodium alginatesolution including 0.05% (by weight) sodium lauryl sulfate in ahalf-liter beaker. Specifically, the drops were added to the shoulder ofa one inch diameter vortex and allowed to dwell for about 20 minutesbefore being removed. The resulting encapsulated beads are cast onto ascreen to be rinsed twice with de-ionized water to wash away anyunreacted alginate solution. The encapsulated beads are dried at 60° C.for 24 hours. The dried encapsulated beads were stable and had adiameter of less than 10,000 micrometers.

EXAMPLE 29

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate various polymers.

Two types of polymers, polyacrylic acid (commercially available fromSigma-Aldrich Co., St. Louis, Mo.) and polyvinyl butyral (available asButvar® B-74 from Solutia, Inc., St. Louis, Mo.), were encapsulated. Toencapsulate polyacrylic acid, polyacrylic acid was utilized to produce amilled (24 hours with one quarter inch zirconium grinding media) 10% (byweight) calcium chloride/89% (by weight) mineral oil (available fromPenreco, Dickinson, Tex.)/1% (by weight) polyacrylic acid blend in a250-gram jar to form a dispersion. Essentially all of the dispersion wasthen added dropwise to 200 grams of a 0.5% (by weight) sodium alginatesolution including 0.05% (by weight) sodium lauryl sulfate in ahalf-liter beaker. Specifically, the drops were added to the shoulder ofa one inch diameter vortex and allowed to dwell for about 20 minutesbefore being removed. The resulting encapsulated beads are cast onto ascreen to be rinsed twice with de-ionized water to wash away anyunreacted alginate solution. The encapsulated beads are dried at 60° C.for 24 hours. The dried encapsulated beads were stable and had adiameter of less than 10,000 micrometers.

To encapsulate polyvinyl butyral, the method as described above forencapsulating polyacrylic acid was repeated with the exception ofreplacing polyacrylic acid with polyvinyl butyral. Similar to theencapsulated polyacrylic acid above, the encapsulated beads containingpolyvinyl butyral were stable and had a diameter of less than 10,000micrometers.

EXAMPLE 30

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate three different water soluble salts.

The three types of water soluble salts encapsulated were: zinc nitrate,copper nitrate, and zinc acetate (all commercially available fromSigma-Aldrich Co., St. Louis, Mo.). To encapsulate zinc nitrate, zincnitrate was utilized to produce a milled (24 hours with one quarter inchzirconium grinding media) 10% (by weight) calcium chloride/89% (byweight) mineral oil (available from Penreco, Dickinson, Tex.)/1% (byweight) zinc nitrate blend in a 250-gram jar to form a dispersion.Essentially all of the dispersion was then added dropwise to 200 gramsof a 0.5% (by weight) sodium alginate solution including 0.05% (byweight) sodium lauryl sulfate in a half-liter beaker. Specifically, thedrops were added to the shoulder of a one inch diameter vortex andallowed to dwell for about 20 minutes before being removed. Theresulting encapsulated beads are cast onto a screen to be rinsed twicewith de-ionized water to wash away any unreacted alginate solution. Theencapsulated beads are dried at 60° C. for 24 hours. The driedencapsulated beads were stable and had a diameter of less than 10,000micrometers.

To encapsulate copper nitrate and zinc acetate, the method as describedabove for encapsulating zinc nitrate was repeated for each water solublesalt with the exception of replacing zinc nitrate with either coppernitrate or zinc acetate. Similar to the encapsulated zinc nitrate above,the encapsulated beads containing either the copper nitrate or zincacetate were stable and had a diameter of less than 10,000 micrometers.

EXAMPLE 31

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate calcium carbonate.

To encapsulate calcium carbonate, calcium carbonate (commerciallyavailable from Sigma-Aldrich Co., St. Louis, Mo.) was utilized toproduce a milled (24 hours with one quarter inch zirconium grindingmedia) 10% (by weight) calcium chloride/89% (by weight) mineral oil(available from Penreco, Dickinson, Tex.)/1% (by weight) calciumcarbonate blend in a 250-gram jar to form a dispersion. Essentially allof the dispersion was then added dropwise to 200 grams of a 0.5% (byweight) sodium alginate solution including 0.05% (by weight) sodiumlauryl sulfate in a half-liter beaker. Specifically, the drops wereadded to the shoulder of a one inch diameter vortex and allowed to dwellfor about 20 minutes before being removed. The resulting encapsulatedbeads are cast onto a screen to be rinsed twice with de-ionized water towash away any unreacted alginate solution. The encapsulated beads aredried at 60° C. for 24 hours. The dried encapsulated beads were stableand had a diameter of less than 10,000 micrometers.

EXAMPLE 32

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate two different metals.

The metals that were encapsulated were iron and silver (eachcommercially available from Sigma-Aldrich Co., St. Louis, Mo.). Toencapsulate iron, iron was utilized to produce a milled (24 hours withone quarter inch zirconium grinding media) 10% (by weight) calciumchloride/89% (by weight) mineral oil (available from Penreco, Dickinson,Tex.)/1% (by weight) iron blend in a 250-gram jar to form a dispersion.Essentially all of the dispersion was then added dropwise to 200 gramsof a 0.5% (by weight) sodium alginate solution including 0.05% (byweight) sodium lauryl sulfate in a half-liter beaker. Specifically, thedrops were added to the shoulder of a one inch diameter vortex andallowed to dwell for about 20 minutes before being removed. Theresulting encapsulated beads are cast onto a screen to be rinsed twicewith de-ionized water to wash away any unreacted alginate solution. Theencapsulated beads are dried at 60° C. for 24 hours. The encapsulatedbeads were stable and had a diameter of less than 10,000 micrometers.

To encapsulate silver, the method as described above for encapsulatingiron was replaced with the exception of replacing iron with silver.Similar to the encapsulated iron above, the encapsulated beadscontaining silver were stable and had a diameter of less than 10,000micrometers.

EXAMPLE 33

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate Marathon® 150, which is acommercially available plasticizer.

To encapsulate Marathon® 150, Marathon® 150 (available from MarathonAshland Petroleum LLC, Garyville, La.) was utilized to produce a milled(24 hours with one quarter inch zirconium grinding media) 10% (byweight) calcium chloride/89% (by weight) mineral oil (available fromPenreco, Dickinson, Tex.)/1% (by weight) Marathon® 150 blend in a250-gram jar to form a dispersion. Essentially all of the dispersion wasthen added dropwise to 200 grams of a 0.5% (by weight) sodium alginatesolution including 0.05% (by weight) sodium lauryl sulfate in ahalf-liter beaker. Specifically, the drops were added to the shoulder ofa one inch diameter vortex and allowed to dwell for about 20 minutesbefore being removed. The resulting encapsulated beads are cast onto ascreen to be rinsed twice with de-ionized water to wash away anyunreacted alginate solution. The encapsulated beads are dried at 60° C.for 24 hours. The dried encapsulated beads were stable and had adiameter of less than 10,000 micrometers.

EXAMPLE 34

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate various acids.

The acids that were encapsulated included: boric acid, citric acid,succinic acid, salicylic acid, and benzoic acid (all commerciallyavailable from Sigma-Aldrich Co., St. Louis, Mo.). To encapsulate boricacid, boric acid was utilized to produce a milled (24 hours with onequarter inch zirconium grinding media) 10% (by weight) calciumchloride/89% (by weight) mineral oil (available from Penreco, Dickinson,Tex.)/1% (by weight) boric acid blend in a 250-gram jar to form adispersion. Essentially all of the dispersion was then added dropwise to200 grams of a 0.5% (by weight) sodium alginate solution including 0.05%(by weight) sodium lauryl sulfate in a half-liter beaker. Specifically,the drops were added to the shoulder of a one inch diameter vortex andallowed to dwell for about 20 minutes before being removed. Theresulting encapsulated beads are cast onto a screen to be rinsed twicewith de-ionized water to wash away any unreacted alginate solution. Theencapsulated beads are dried at 60° C. for 24 hours. The driedencapsulated beads were stable and had a diameter of less than 10,000micrometers.

To encapsulate the other four acids, the method as described above forencapsulating boric acid was repeated for each of the other four acidswith the exception of replacing boric acid with one of the other fouracids. Similar to the encapsulated boric acid above, the encapsulatedbeads containing the other acids were stable and had a diameter of lessthan 10,000 micrometers.

EXAMPLE 35

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate ammonium hydroxide.

To encapsulate ammonium hydroxide, ammonium hydroxide (commerciallyavailable from Sigma-Aldrich Co., St. Louis, Mo.) was utilized toproduce a milled (24 hours with one quarter inch zirconium grindingmedia) 10% (by weight) calcium chloride/89% (by weight) mineral oil(available from Penreco, Dickinson, Tex.)/1% (by weight) ammoniumhydroxide blend in a 250-gram jar to form a dispersion. Essentially allof the dispersion was then added dropwise to 200 grams of a 0.5% (byweight) sodium alginate solution including 0.05% (by weight) sodiumlauryl sulfate in a half-liter beaker. Specifically, the drops wereadded to the shoulder of a one inch diameter vortex and allowed to dwellfor about 20 minutes before being removed. The resulting encapsulatedbeads are cast onto a screen to be rinsed twice with de-ionized water towash away any unreacted alginate solution. The encapsulated beads aredried at 60° C. for 24 hours. The dried encapsulated beads were stableand had a diameter of less than 10,000 micrometers.

EXAMPLE 36

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate various pigments.

Three types of pigments, titanium dioxide (commercially available fromDuPont Co., Edge Moor, Del.), zinc oxide (commercially available fromSigma-Aldrich Co., St. Louis, Mo.), and magnesium oxide (commerciallyavailable from Sigma-Aldrich Co., St. Louis, Mo.), were encapsulated. Toencapsulate titanium dioxide, titanium dioxide was utilized to produce amilled (24 hours with one quarter inch zirconium grinding media) 10% (byweight) calcium chloride/89% (by weight) mineral oil (available fromPenreco, Dickinson, Tex.)/1% (by weight) titanium dioxide blend in a250-gram jar to form a dispersion. Essentially all of the dispersion wasthen added dropwise to 200 grams of a 0.5% (by weight) sodium alginatesolution including 0.05% (by weight) sodium lauryl sulfate in ahalf-liter beaker. Specifically, the drops were added to the shoulder ofa one inch diameter vortex and allowed to dwell for about 20 minutesbefore being removed. The resulting encapsulated beads are cast onto ascreen to be rinsed twice with de-ionized water to wash away anyunreacted alginate solution. The encapsulated beads are dried at 60° C.for 24 hours. The dried encapsulated beads were stable and had adiameter of less than 10,000 micrometers.

To encapsulate zinc oxide or magnesium oxide, the method as describedabove for encapsulating titanium dioxide was repeated with the exceptionof replacing titanium dioxide with either zinc oxide or magnesium oxide.Similar to the encapsulated titanium dioxide above, the encapsulatedbeads containing either zinc oxide or magnesium oxide were stable andhad a diameter of less than 10,000 micrometers.

EXAMPLE 37

In this Example, the alginate microencapsulation method of the presentdisclosure was used to encapsulate various fuels.

Three types of fuels, toluene (commercially available from HawkinsChemical, Minneapolis, Minn., heptane (commercially available fromHawkins Chemical, Minneapolis, Minn.), and naptha (commerciallyavailable from Phipps Products Corporation, Boston, Mass.), wereencapsulated. To encapsulate toluene, toluene was utilized to produce amilled (24 hours with one quarter inch zirconium grinding media) 10% (byweight) calcium chloride/89% (by weight) mineral oil (available fromPenreco, Dickinson, Tex.)/1% (by weight) toluene blend in a 250-gram jarto form a dispersion. Essentially all of the dispersion was then addeddropwise to 200 grams of a 0.5% (by weight) sodium alginate solutionincluding 0.05% (by weight) sodium lauryl sulfate in a half-literbeaker. Specifically, the drops were added to the shoulder of a one inchdiameter vortex and allowed to dwell for about 20 minutes before beingremoved. The resulting encapsulated beads are cast onto a screen to berinsed twice with de-ionized water to wash away any unreacted alginatesolution. The encapsulated beads are dried at 60° C. for 24 hours. Thedried encapsulated beads were stable and had a diameter of less than10,000 micrometers.

To encapsulate the heptane or naptha, the method as described above forencapsulating toluene was repeated with the exception of replacingtoluene with either heptane or naptha. Similar to the encapsulatedtoluene above, the encapsulated beads containing either heptane ornaptha were stable and had a diameter of less than 10,000 micrometers.

EXAMPLE 38

In this Example, a self-warming wet wipe including microencapsulatedheat delivery vehicles was produced according to the present disclosure.The temperature increase in the wet wipe upon activation of the contentsof the microencapsulated heat delivery vehicles was then analyzed.

To produce the self-warming wet wipe, two layers of a coform basesheet,each made of 30% (by weight) polypropylene fibers and 70% (by weight)wood pulp fibers and having a basis weight of 30 grams per square meter,were heat sealed together on three sides to form a pouch (2″×2″).Microencapsulated heat delivery vehicles were made by first producingthe microencapsulated heat delivery vehicles in accordance with a methoddescribed above and then 2.24 grams of the microencapsulated heatdelivery vehicles were placed inside the pouch and the fourth side ofthe pouch was heat sealed to form a wipe.

To produce the microencapsulated heat delivery vehicles, anhydrousmagnesium chloride (about 20 micrometers in diameter) was introducedinto mineral oil to form a 25% (by weight) magnesium chloride/75% (byweight) mineral oil composition that was mixed together thoroughly andhad a resulting viscosity (25° C.) of about 300 centipoise. Thiscomposition was introduced dropwise from a separatory funnel into twoliters of a sodium alginate solution (1% by weight in de-ionized water,300 centipoise at 25° C.) and allowed to dwell in the solution for about30 minutes under sufficient stirring to keep the drops formed uponaddition into the sodium alginate solution separate. Most drops of thecomposition added were about 3 millimeters in diameter. After 30 minutesdwell time the formed microencapsulated beads were removed from thesodium alginate solution and rinsed three times with de-ionized waterand cast to air-dry at room temperature overnight. Stablemicroencapsulated heat delivery vehicles were formed having a diameterof about 3 millimeters.

The wipe containing the microencapsulated heat delivery vehicles wasthen wetted with 0.7 grams wetting solution using a spray bottle. Thewetting solution comprised the following components: about 98.18% (byweight) water; about 0.6% (by weight) potassium laureth phosphate; about0.30% (by weight) glycerin; about 0.30% (by weight) polysorbate 20;about 0.20% (by weight) tetrasodium EDTA; about 0.20% (by weight) DMDMhydrantoin; about 0.15% (by weight) methylparaben; about 0.07% (byweight) malic acid; about 0.001% (by weight) aloe barbadensis; and about0.001% (by weight) tocopheryl acetate.

Once the wet wipe was produced, the temperature of the wet wipe wasmeasured by folding the wipe in half and inserting a Type K thermocouple(available from VWR International, West Chester, Pa.) into the center ofthe folded wipe. The wipe was then introduced into a standardpolyethylene bag, which was then laid onto six layers of paper toweling(commercially available as Scott Brand, Kimberly-Clark Worldwide, Inc.,Neenah, Wis.). The temperature of the wipe was measured to be 29.9° C.

The microencapsulated heat delivery vehicles were then broken using aCoorstek 60314 pestle (available from CoorsTek, Golden, Colo.). Thebroken shells of the microencapsulated heat delivery vehicles remainedinside of the wipe. As the microencapsulated heat delivery vehicles werecrushed and their contents exposed to the wetting solution, the wet wipebegan warming. The warming of the wet wipe was analyzed by using adigital thermometer (available from VWR International, West Chester,Pa.), which recorded at a 3 second interval. The temperature wasrecorded for 90 seconds, starting from the time the microencapsulatedheat delivery vehicles were crushed. The temperature of the wet wipeincreased to a temperature of 41.2° C.

EXAMPLE 39

In this Example, samples of pan coated alginate microencapsulated heatdelivery vehicles having fugitive shell layers made from variousmaterials were produced and analyzed for particle strength. Controlsamples of pan coated alginate microencapsulated heat delivery vehicleswithout fugitive shell layers were also produced and analyzed forparticle strength.

Nine control samples of 49-1 pan coated alginate microencapsulated heatdelivery vehicle without fugitive shell layers were produced using themethod of Example 12. Nine samples of 49-2 pan coated alginatemicroencapsulated heat delivery vehicle having a fugitive shell layermade from Ticacel® HV (commercially available from TIC Gum, Belcamp,Md.) were produced using the method of Example 18. Six samples of 49-4pan coated alginate microencapsulated heat delivery vehicle having afugitive shell layer made from PURE-COTE® B-792 starch (commerciallyavailable from Grain Processing Corporation, Muscatine, Iowa) wereproduced using the method of Example 20. Nine samples of 49-5 pan coatedalginate microencapsulated heat delivery vehicle having a fugitive shelllayer made from polyvinyl alcohol (commercially available fromSigma-Aldrich Co., St. Louis, Mo.) were produced using the method ofExample 17. Seven samples of 49-3 pan coated alginate microencapsulatedheat delivery vehicle having a fugitive shell layer made from Gum ArabicFT (commercially available from TIC Gum, Belcamp, Md.) were producedusing the method of Example 19. Eight samples of 49-6 pan coatedalginate microencapsulated heat delivery vehicle having a fugitive shelllayer made from Gum Arabic FT were produced using the same method asused to produce the 49-3 samples except that four coats of Gum Arabic FTwere applied. Five samples of 49-7 pan coated alginate microencapsulatedheat delivery vehicle having a fugitive shell layer made from Gum ArabicFT were produced using the same method as used to produce the 49-3samples and then the Gum Arabic FT was removed using the method as setforth in Example 21.

To test particle strength, a TA Texture Analyzer (Software Version 1.22)(available from Texture Technologies Corporation, Scarsdale, N.Y.) wasused. Specifically, a single particle of each sample was independentlyplaced on a polycarbonate plate and force measurements were made using aone-quarter inch to one inch diameter flat probe, moving at a rate ofabout 0.25 millimeter/second to about 5.0 millimeters/second. As theforce load was applied by the probe, the particle deformed until itcracked or collapsed. Generally, the deformation of the particlecontinues until the applied force increases exponentially, indicatingthat the shell of the particle has been ruptured. The results of themeasurements were averaged for each type of sample and are shown inTable 6 and FIGS. 18-24.

TABLE 6 Pan Coated Alginate Averaged Force (grams) MicroencapsulatedHeat required to rupture sample Delivery Vehicle Sample particle 49-11123 49-2 1274 49-3 707 49-4 1197 49-5 1131 49-6 849 49-7 Not Detectable

As shown in Table 6 and FIGS. 18-24, on average, more force was requiredto crush samples of 49-2, 49-4, and 49-5 than samples of 49-1.Specifically, the samples of 49-2, which have a fugitive shell layermade of Ticacel® HV Powder, required the greatest force to rupture,indicating that Ticacel® HV Powder provides the greatest protectionamong the materials in the Example against rupturing. The samples of49-4 and 49-5, which have fugitive shell layers made of starch andpolyvinyl alcohol, respectively, also provide improved protectionagainst rupturing. The samples having fugitive shell layers made of GumArabic FT were more easily ruptured.

Additionally, as shown in FIGS. 18-24, samples of 49-2, 49-4, and 49-5did not appear to deform as much as samples of 49-1, 49-3, and 49-6, asindicated by the steeper slope of the force curves.

EXAMPLE 40

In this Example, the biocide, polyhexamethylene biguanide, was evaluatedat elevated temperatures to determine its efficacy.

This Example utilized 1.5-milliliter tubes containing a 1-milliliterblend of phosphate-buffered saline (pH 7.2) and 5% (w/v) bovine serumalbumin soil. The tubes were placed in electric heat blocks set for 22°C., 30° C., 40° C. and 50° C., respectively. The tubes remained in theelectric heat blocks for approximately 10 minutes.

After 10 minutes, 0.005% (by weight) active polyhexamehtylene biguanide(PHMB) (commercially available as Cosmocil® CQ from Arch Biocides, Inc.,United Kingdom) was added to two tubes at each temperature level.Duplicate tubes without PHMB at each temperature were also made.

The tubes were then vortexed and Methicillin-resistant Staphylococcusaureus (approximately 1×10⁵ colony forming units (CFU)) was then addedto each tube. All of the tubes were then placed back into the heatblocks at their respective temperatures.

Following a 10-minute contact time, 0.1 milliliters of each sample wastransferred to 0.9 milliliters letheen broth to neutralize the PHMBactivity. The letheen samples were then plated in duplicate on TrypticSoy agar plates using a WASP2 spiral plater (commercially available fromDon Whitley Scientific, Ltd., Yorkshire, United Kingdom). The plateswere inverted and incubated at 37±2° C. for 48 hours.

After 48 hours, the plates were evaluated using a total plate count todetermine the biocidal efficacy of each sample. The results are shown inTable 7.

TABLE 7 Heat blocks @ various Total CFU Recovered temperatures (n = 2)MRSA LOG₁₀ Reduction 22° C. 5.6 2.1 22° C.; 0.005% PHMB 3.5 30° C. 5.72.8 30° C.; 0.005% PHMB 2.9 40° C. 5.6 3.5 40° C.; 0.005% PHMB 2.1 50°C. 5.5 >3.5 50° C.; 0.005% PHMB <2

As shown in Table 7, greater efficacy of the 0.005% (by weight) activePHMB was observed as the temperature increased. Specifically, a greaterthan 1.4 LOG₁₀ difference in efficacy was observed between experimentsconducted at 22° C. as compared to those conduced at 50° C.

EXAMPLE 41

In this Example, magnesium chloride was evaluated for its ability toincrease biocidal efficacy when used in combination with the biocide,polyhexamethylene biguanide.

A 1.5-milliliter tube was prepared using magnesium chloride in water.

Two control samples were also prepared. One control sample was filledwith 0.850 milliliters magnesium chloride. A second control sample wasprepared by introducing 0.850 milliliters sterile water.

A biocide agent, polyhexamethylene biguanide (PHMB), which has a finalconcentration of 0.00025% was then introduced into one tube comprisingmagnesium chloride and water and to the one control tube containingsolely water. The tubes were then vortexed until an increase intemperature was observed.

0.05 milliliters of 1×10⁷ CFU/milliliter culture of Staphylococcusaureus was added to each tube. After a 15-minute contact time, 0.1milliliters of each tube was transferred into 0.9 milliliters letheenbroth. To the broth, 10 milligrams/milliliter sodium thiosulfate wasalso added. The tubes were again vortexed. After vortexing, 0.1milliliters of each tube was plated on Tryptic soy agar plates. Theplates were inverted and incubated at 37° C. for 24 hours. An inoculumcontrol plate was also plated to determine the concentration of theinoculum

After 24 hours, the plates were evaluated using a total plate count todetermine the biocidal efficacy of each sample. The results are shown inTable 8.

TABLE 8 PHMB Magnesium Chloride LOG₁₀ Concentration (%) Concentration(%) recovered 0.00025 0 4.8 0 50 1.9 0.00025 50 1.0

As shown in Table 8, the tube comprising magnesium chloride incombination with PHMB inhibited Staphylococcus aureus better than theother tubes.

When introducing elements of the present disclosure or the preferredembodiment(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

As various changes could be made in the above constructions withoutdeparting from the scope of the disclosure, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

1. A wet wipe comprising a fibrous sheet material, a wetting solution, amicroencapsulated heat delivery vehicle, and a first phase changematerial, wherein the first phase change material has a particle size offrom about 300 to about 500 micrometers, the microencapsulated heatdelivery vehicle comprising an encapsulation layer that surrounds a corecomposition, wherein the core composition comprises a matrix material,an encapsulating activator, and a heating agent, the heating agent beingsurrounded by a hydrophobic wax material.
 2. The wet wipe as set forthin claim 1 wherein first phase change material has a melting point offrom about 22° C. to about 50° C.
 3. The wet wipe as set forth in claim2 wherein the first phase change material is selected from the groupconsisting of n-Tetracosane, n-Tricosane, n-Docosane, n-Heneicosane,n-Eicosane, n-Nonadecane, n-Octadecane, n-Heptadecane, and combinationsthereof.
 4. The wet wipe as set forth in claim 1 further comprising asecond phase change material, wherein the second phase change materialis different than the first phase change material.
 5. The wet wipe asset forth in claim 4 wherein the second phase change material has amelting point of from about 50° C. to about 65° C.
 6. The wet wipe asset forth in claim 4 wherein the second phase change material isselected from the group consisting of n-Tetracosane, n-Tricosane,n-Docosane, n-Heneicosane, n-Eicosane, n-Nonadecane, n-Octadecane,n-Heptadecane, and combinations thereof.
 7. The wet wipe as set forth inclaim 1 wherein the first phase change material particle ismicroencapsulated.
 8. A dry wipe comprising a fibrous sheet material, amicroencapsulated heat delivery vehicle, and a first phase changematerial, wherein the first phase change material has a particle size offrom about 300 to about 500 micrometers, the microencapsulated heatdelivery vehicle comprising an encapsulation layer that surrounds a corecomposition, wherein the core composition comprises a matrix material,an encapsulating activator, and a heating agent, the heating agent beingsurrounded by a hydrophobic wax material.
 9. The dry wipe as set forthin claim 8 wherein first phase change material has a melting point offrom about 22° C. to about 50° C.
 10. The dry wipe as set forth in claim9 wherein the first phase change material is selected from the groupconsisting of n-Tetracosane, n-Tricosane, n-Docosane, n-Heneicosane,n-Eicosane, n-Nonadecane, n-Octadecane, n-Heptadecane, and combinationsthereof.
 11. The dry wipe as set forth in claim 8 further comprising asecond phase change material, wherein the second phase change materialis different than the first phase change material.
 12. The dry wipe asset forth in claim 11 wherein the second phase change material has amelting point of from about 50° C. to about 65° C.
 13. The dry wipe asset forth in claim 11 wherein the second phase change material isselected from the group consisting of n-Tetracosane, n-Tricosane,n-Docosane, n-Heneicosane, n-Eicosane, n-Nonadecane, n-Octadecane,n-Heptadecane, and combinations thereof.
 14. The dry wipe as set forthin claim 8 wherein the first phase change material particle ismicroencapsulated.